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I propose the following theory: rational investors allocate capital to maximize the probability-weighted geometric mean of payoffs. I present the theory’s rationale and investigate its implications. I find that diversification increases cumulative returns and asset values are relative. The theory does not make assumptions about investors’ risk preferences and explains the “risk premium” without using the utility function concept. In a world of rational, risk indifferent investors the market tends to a stable equilibrium characterized by all investors holding the market. I calculate equilibrium prices for a simple model. The theory uses a unique discount rate (to account for time value of money) and ignores the required rate of return concept. The theory addresses some of the CAPM’s inconsistencies. I conclude the theory is coherent and useful in explaining observable finance phenomena.

After publishing its first report in September 1997, the Own Funds Working Group, in agreement with the European Committee of Central Balance Sheet Offices, decided to continue its work in order to gain a better understanding of the differences in financing structures between countries. To this end, the Group decided firstly to broaden the review period from 1986 to 1996. The compilation of figures and ratios over a longer period is advantageous in a number of ways. It not only enables an assessment of trends in financing structures in each country, but also of any changes in the ranking of the different countries involved. Furthermore, it gives an insight into the influence of cyclical and structural factors on this ranking. The Group also set itself the objective of not only taking a closer look at the influence of institutional factors The study was based, as the previous study, on incorporated companies (partnerships and sole proprietorships are therefore excluded) of the manufacturing industry, which is uniformly defined across all the countries. Once again, five size brackets according to turnover expressed in euros are analyzed. The size-based approach is essential because the aggregate values conceal the diversity of the situations in the various countries, especially in Germany where the results are strongly influenced by large firms. The two statistical parameters used are the weighted mean and the median. Moreover, to gain a better understanding of the influence of financing needs, assets have been broken down into their main items. As previously, efforts have been made to align methodologies so that the analyses cover variables that are as homogenous as possible from country to country.

We propose a model with heterogeneous interacting traders which can explain some of the stylized facts of stock market returns. In the model, synchronization effects, which generate large fluctuations in returns, can arise purely from communication and imitation among traders. The key element in the model is the introduction of a trade friction which, by responding to price movements, creates a feedback mechanism on future trading and generates volatility clustering. The model also reproduces the empirically observed positive cross- correlation between volatility and trading volume.

This paper reviews some of the phenomenological models which have been introduced to incorporate the scaling properties of financial data. It also illustrates a microscopic model, based on heterogeneous interacting agents, which provides a possible explanation for the complex dynamics of markets' returns. Scaling and multi-scaling analysis performed on the simulated data is in good quantitative agreement with the empirical results., Comment: Paper presented at the Disordered and Complex Systems s conference, King's College London, July 2000

This is a preliminary draft of an Invited Symposium paper for the World Congress of the Econometric Society to be held in Seattle in August 2000. We discuss the strong connections between auction theory and 'standard' economic theory, and argue that auction-theoretic tools and intuitions can provide useful argument and insights in a broad range of mainstream economic settings that do not, at first sight, look like auctions. We also discuss some more obvious applications, especially to industrial organization.

In this paper we present a rather general phenomenological theory of tick-by-tick dynamics in financial markets. Many well-known aspects, such as the L\'evy scaling form, follow as particular cases of the theory. The theory fully takes into account the non-Markovian and non-local character of financial time series. Predictions on the long-time behaviour of the waiting-time probability density are presented. Finally, a general scaling form is given, based on the solution of the fractional diffusion equation., Comment: 11 pages, no figures, LaTeX2e, submitted to Physica A

Twenty-two significant bubbles followed by large crashes or by severe corrections in the Argentinian, Brazilian, Chilean, Mexican, Peruvian, Venezuelan, Hong-Kong, Indonesian, Korean, Malaysian, Philippine and Thai stock markets indices are identified and analysed for log-periodic signatures decorating an average power law acceleration. We find that log-periodic power laws adequately describe speculative bubbles on these emerging markets with very few exceptions and thus extend considerably the applicability of the proposed rational expectation model of bubbles and crashes which has previously been developed for the major financial markets in the world. This model is essentially controlled by a crash hazard rate becoming critical due to a collective imitative/herding behavior of traders. Furthermore, three of the bubbles are followed by a log-periodic ``anti-bubble'' previously documented for the decay of the Japanese Nikkei starting in Jan. 1990 and the price of Gold starting in Sept. 1980 thus rendering a qualitative symmetry of bubble and anti-bubble around the date of the peak of the market. A set of secondary western stock market indices (London, Sydney, Auckland, Paris, Madrid, Milan, Zurich) as well as the Hong-Kong stock market are also shown to exhibit well-correlated log-periodic power law anti-bubbles over a period 6-15 months triggered by a rash of crises on emerging markets in the early 1994. As the US market declined by no more than 10% during the beginning of that period and quickly recovered, this suggests that these smaller stock western markets can ``phase lock'' (in a weak sense) not only because of the over-arching influence of Wall Street but also independently of the current trends on Wall Street due to other influences., Comment: 36 pages including 42 figures and 7 tables. Subm. to J. of Risk

We study the efficiency of the equilibrium price in a centralized, order-driven market where many asymmetrically informed traders are active for many periods. We show that asymmetries of information can lead to sub-optimal information revelation with respect to the symmetric case. In particular, we assess that the more precise the information the higher the incentive to reveal it, and that the value of private information is related to the volume of exogenous trade present on the market. Moreover, we prove that any informed trader, whatever his information, reveals his private signal during an active phase of the market, concluding that long pre-opening phases are not effective as an information discovering device in the presence of strategic players.

With a constant new stream of financial services coming to the market, each often more exotic and complicated than the last, the financial services industry, which includes commodity derivatives exchanges, brokerage houses and banks providing price risk reduction services (the so-called hedging services), is one of the fastest growing industries. In order to assure survival, these companies show a rapid product innovation. However, for commodity derivatives the risk of failure is considerable. This paper presents a new and integrative approach towards commodity derivatives management, which makes it easier to gain insight into the viability of new commodity derivatives before introduction, to assess and improve the viability of existing commodity derivatives

Futures exchanges are in constant search of futures contracts that will generate a profitable level of trading volume. In this context, it would be interesting to determine what effect the introduction of new futures contracts have on the trading volume of the contracts already listed. The introduction of new futures contracts may lead to a volume increase for those contracts already listed and hence, contribute to the success of a futures exchange. On the other hand, the introduction of new futures contracts could lead to a volume decrease for the contracts already listed, thereby undermining the success of the futures exchange accordingly. Using a multi-product hedging model in which the perspective has been shifted from portfolio to exchange management, we study these effects. Using data from two exchanges that are different regarding market liquidity (Amsterdam Exchanges versus Chicago Board of Trade) we show the usefulness of the proposed tool. Our findings have several important implications for a futures exchange's innovation policy.

In this short note we show how virtual arbitrage opportunities can be modelled and included in the standard derivative pricing without changing the general framework., Latex, 6 pages, Proschal'nii poklon

Value-at-Risk, known as VaR, gives a prediction of potential portfolio losses, with a certain level of confidence, that may be encountered over a specified time period due to adverse price movements in the portfolio's assets. For example, a VaR of 1 million dollars at the 95% level of confidence implies that overall portfolio losses should not exceed 1 million dollars more than 5% of the time over a given holding period. This research examines the effectiveness of VaR measures, developed using alternative estimation techniques, in predicting large losses in the cattle feeding margin. Results show that several estimation techniques, both parametric and non-parametric, provide well- calibrated estimates of VaR such that violations (losses exceeding the VaR estimate) are commensurate with the desired level of confidence. In particular, estimates developed using JP Morgan's Risk Metrics methodology appear robust for instruments that have linear payoff structures such as cash commodity prices.

We generalize the Arbitrage Pricing Theory (APT) to include the contribution of virtual arbitrage opportunities. We model the arbitrage return by a stochastic process. The latter is incorporated in the APT framework to calculate the correction to the APT due to the virtual arbitrage opportunities. The resulting relations reduce to the APT for an infinitely fast market reaction or in the case where the virtual arbitrage is absent. Corrections to the Capital Asset Pricing Model (CAPM) are also derived., Comment: Latex, 12 pages

We study the volatility of the MIB30-stock-index high-frequency data from November 28, 1994 through September 15, 1995. Our aim is to empirically characterize the volatility random walk in the framework of continuous-time finance. To this end, we compute the index volatility by means of the log-return standard deviation. We choose an hourly time window in order to investigate intraday properties of volatility. A periodic component is found for the hourly time window, in agreement with previous observations. Fluctuations are studied by means of detrended fluctuation analysis, and we detect long-range correlations. Volatility values are log-stable distributed. We discuss the implications of these results for stochastic volatility modelling., Comment: 9 pages, 4 figures, LaTeX2e, to be published in Physica A

We propose a development process of commodity futures contracts in which the decisions and wishes of potential customers are investigated simultaneously with the necessary technical properties that need to be met for trading to take place. Within this framework the relationship between trading volume and hedging effectiveness is examined taking both basis risk and market depth risk into account, and the relationship between owner-manager's characteristics and the probability of using futures is examined, taking latent variables and the heterogeneity of owner-managers into account. The relationships are tested on a set of data gathered in a stratified sample of 440 owner-managers by means of computer-assisted personal interviews and on transaction-specific futures data. Structural equation models and multiple regression models are used to validate the relationships. The hedging effectiveness and the variables that play a role in the owner-manager's use of futures are related to the tools of the exchange.

We study a source of bias in value-at-risk estimates that has not previously been recognized. Because value-at-risk estimates are based on past data, a trader will often have a good understanding of the errors in the value-at-risk estimate, and it will be possible for her to choose portfolios for which she knows that the value-at-risk estimate is less than the “true” value at risk. Thus, the trader will be able to take on more market risk than risk limits based on value-at-risk permit. Biases can also arise if she does not have a good understanding of the errors, but uses the estimated covariance matrix to achieve certain portfolio objectives. We assess the magnitude of these biases for three different assumptions about the motivations and behavior of the trader and find that in all cases, value-at-risk estimates are systematically downward biased. In some circumstances the biases can be very large. Our study of the distributions of the biases also suggests a way to adjust the estimates to “correct” the biases.

Previous research has shown that simple trading rules can be useful tools for evaluating financial models. Here we introduce trading rules which are selected by an artificially intelligent agent who learns from experience - an Artificial Technical Analyst. We show that the rules used by this agent can lead to the recognition of subtle regularities in return processes whilst suffering from lesser data-mining problems than other rules commonly used as model evaluation devices. The relationship between the efficiency of financial markets and the efficacy of technical analysis is investigated and it is shown that the Artificial Technical Analyst can be used to provide a quantifiable measure of market efficiency. The measure is applied to the DJIA daily index from 1962 to 1986 and it is shown that a quantification of efficiency based on the profits of an Artificial Technical Analyst can lead to interesting results concerning the behaviour of other investors.

In a novel approach, standard and implied binomial trees are completely specified in terms of two basic inputs: the ending nodal probability distribution and a linear weight function which governs the stochastic process resulting in that distribution. Several key economic principles, such as no interior arbitrage, are intuitively related to these basic inputs. A simple and computationally efficient three-step algorithm, common to all binomial trees, is found. Noting that the currently used linear weight function is unnecessarily restrictive, a binomial tree even more versatile is introduced, the generalized binomial tree. Applications to recovering the stochastic process implied in (European, American, or exotic) options of several times-to-expiration are developed.

In this paper we present a solution to the problem of pricing guarantees of minimum returns on pension fund contributions. These guarantees exist by law in Colombia and cover all pension fund contributions made to the country's private pension fund administration companies (AFPs). As of September 1997, the funds were collecting contributions of 2.5 million affiliates with an accumulated capital of 1.8 billion dollars starting from zero in 1994. Two types of guarantees exist: on obligatory contributions and on voluntary contributions. The solutions are based on a discrete martingale approach . We show that both guarantees are equivalent to an ''option to exchange.'' However, in the case of voluntary contributions a ceiling on the payoff s must be added. Using a discrete martingale framework and a binomial solution we develop all aspects of the model that are necessary for its practical application in the context of the pension fund guarantees. Binomial formulas are obtained for both forms of guarantees. Besides solving the problem of pricing the guarantees offered by insurance fund, the contributions in terms of options theory of this paper are: i) we adapt the binomila model of options to exchange to relate the relevant parameters of the same to a continuous-time lognormal process; ii) we provide a binomial solution to the problem of an option to exchange with a ceiling. We then investigate the incentives that the current fixed-price system introduces and propose possible systems of incentives that can be used to encourage higher-risk investment by the AFP's and a shift of the fund's portfolio to risky equity and debt. Given the country's effort to encourage capital markets development and the financing of the real sector via private financial markets, this strategy appears to be desirable from the social and economic point of view.

In recent studies the truncated Levy process (TLP) has been shown to be very promising for the modeling of financial dynamics. In contrast to the Levy process, the TLP has finite moments and can account for both the previously observed excess kurtosis at short timescales, along with the slow convergence to Gaussian at longer timescales. I further test the truncated Levy paradigm using high frequency data from the Australian All Ordinaries share market index. I then consider, for the early Levy dominated regime, the issue of option hedging for two different hedging strategies that are in some sense optimal. These are compared with the usual delta hedging approach and found to differ significantly. I also derive the natural generalization of the Black-Scholes option pricing formula when the underlying security is modeled by a geometric TLP. This generalization would not be possible without the truncation., 21 pages in Latex, 6 eps figures

s: An earlier study (Cieply, Paranque, 1996) revealed the existence of a size effect in the determination of the financial structures of French firms over the period 1990-1993. However, this effect only appeared clearly above the 2000 employee threshold and was not sufficient to identify the dominant factors explaining the financial structures observed. We therefore turned to a model that included the determinants of the demand for and supply of financial debt. The main findings of this research are: the importance of credit rationing by demand over the period as a whole and across the population of firms; the absence of any effect of substitution of debt to suppliers for debt to financial institutions, perhaps due to a lack of information about the customers of firms subject to credit rationing by supply; the high frequency of firms with financial links subject to credit rationing by supply, which doubtless corresponds to specific methods for managing cash balances and the production cycle; the fact that listed firms are more often in equilibrium than other firms. The hypothesis of a small business capital gap is borne out only for the smallest businesses, especially as regards long-term debt. However, this finding is not entirely clear-cut. Lastly, the prevalence of each configuration seems to depend more on the movement of interest rates than on their spread.

Throughout the Member States of the European Union, economic policy debate has centred on the terms of corporate financing, and in particular on whether the companies of each country have sufficient equity to compete in a single market. Moreover, faced with the risk of corporate insolvency, credit institutions consider a certain equity level to be one of several indicators of creditworthiness. Given this situation and within the framework of the work of the European Committee of Central Balance Sheet Offices, Germany, Austria, Spain, France and Italy and the second General Directorate of the European Commission invited a working group , to compare the f-inancial autonomy of European industriel companies. This study covered the period 1991 to 1993 and examined several issues. Do corporate equity levels vary according to the country ? Do these levels vary according to company size, regardless of the country? Do small companies have a specific position in each country? This study is based on an évaluation of corporate solvency, given that equity is used by companies and their financial partners to control risk exposure. After a brief reminder of the role of equity, the study sums up the research conducted since the publication in 1958 of the paper by Modigliani and Miller and gives a critical analysis of the empirical findings of intenational comparisons. All such research must begin by identifying and solving the financial and statistical methodological problems inherent to comparisons of the financing conditions of different countries. The work conducted gives rise to clear conclusions. - Corporate equity levels vary from country to country. These differences are at least partially related to variations in taxation, bankruptcy regulations, the organization of the banking system, the relationship between banks and companies and the financing practices of each country. - An overall analysis is insufficient and must be complemented by an analysis by company size. - The situation of the companies in each country can not be evaluated without taking into account financial requirements. - In France, regardless of the size of the company, the share of equity in overall financial resources appears larger than in other countries. Moreover, the difference between the equity of small and medium-sized companies and that of large corporations is narrower than in Germany or Austria. It should also be noted that this company classification is relatively recent in France.

The purpose of the paper is to evaluate and measure the effect of financial liberalization (FL) on bank risk exposure. We pursue these questions by assessing the changes in market-based asset values and risk exposure measures for commercial banks (CB) before and during a FL program. We do this for a sample of three countries: Malaysia, Taiwan and Thailand. We use a model based on the options pricing theory. We obtain estimates of the first and second moment of bank returns using an asset pricing model in which these two moments are a linear projection of a set of conditioning variables. This model was estimated using a GMM statistical procedure. Then we perform regressions explaining the evolution of bank risk measure around the FL event. The analysis and statistical test indicate that risk exposure of banks increases following a FL program, and this as a result of macroeconomic policy as well as changes in management controlled variables. This is so even for banks operating in countries that have undertaken very cautious FL processes such as Thailand and Malaysia. The results tend to support the proposition that moral hazard and bank risk taking may increase following FL. The results also suggest that banking crisis that often have followed FL may be more due to the behavior of banks' managers than previously reported in the FL literature.

We develop and apply a set of hypothesis tests with which to study changes in the angular distribution of points in delay space. Crack and Ledoit (1996) plotted daily stock returns against themselves with one day's lag. (This might be described as a plot in delay space). The graph shows these points collected along several rays from the origin. They correctly attribute this compass rose pattern to discreteness in the data. Asset prices move in discrete ticks. Our testing procedures allow one to test for changes in Crack and Ledoit's compass rose pattern. Our case study gives an example of such a change in distribution being caused by a change in regime. We plot the number of points along a given ray of the compass rose against the angle of that ray. This creates a theta histogram which describes the angular distribution of the points in delay space. We compare this distribution to a standard theta histogram created by a simple bootstrap procedure. The chi-square test is then performed in order to estimate quantitatively the consistency of the actual data with the standard theta histogram. Extensions of this technique are discussed. We apply our technique to an important episode of Russian monetary history. In the late nineteenth century, the credit ruble was a floating currency unlinked to precious metals. Generally, the finance ministry actively intervened to influence the ruble exchange rate. The one exception was during Nicolai Bunge's tenure as finance minister. Bunge's successor, Ivan Vyshnegradsky, was an unusually vigorous interventionist. The shift in regime from Bunge the non-interventionist to Vyshnegradsky the interventionist produced a marked change in the behavior of the ruble exchange rate. The angular distribution in delay space of the ruble's exchange rate against the German mark shifted dramatically under Vyshnegradsky. Hypothesis tests support the view that Vyshnegradsky's activism caused a disproportionate number of points of the compass rose to accumulate on the main diagonals in delay space. The theory of Big Players (Koppl and Yeager 1996) helps to explain why. Our results are consistent with those of Broussard and Koppl (1996) who use a GARCH(1,1) model.

The Tax Act of 1986 changed the tax treatment of tax-exempt municipal bonds for banks. Since banks were the dominant participant in the municipal bond market until 1986, some believe that this resulted in the breakdown of the long-run equilibrium relationship between municipal and U.S. treasury securities of equal maturity. We present evidence that there was a significant break in the relationship muncipal and Treasury bonds around the time of the Tax Act but that break is in the mean of the equilibrium relationship and does not change the "slope" parameter that links the two interest rates in the long-run. Once this break is accounted for using a dummy variable the relationship between municipal and Treasury yields remains intact.

The focus of this study is the habitual speculator in commodity futures markets. The speculator's activity broadens a market, creates essential liquidity, and performs an irreplaceable pricing function. Working knowledge of the profiles and motivations of habitual speculators is essential to both market theorist and policy makers. Responses to a 73 question survey were collected directly from retail commodity brokers with offices in Alabama. Each questionnaire recorded information on an individual commodity client who had traded for an extended period of time. The typical trader studied is a married, white male, age 52. He is affluent and well educated. He is a self-employed business owner who can recover from financial setbacks. He is a politically right wing conservative involved in the political process. He assumes a good deal of risk in most phases of his life. He is both an aggressive investor and an active gambler. This trader does not consider preservation of his commodity capital to be a very high trading priority. As a result, he rarely uses stop loss orders. He wins more frequently than he loses (over 51% of the time) but is an overall net loser in dollar terms. In spite of recurring trading losses, he has never made any substantial change in his basic trading style. To this trader, whether he won or lost on a particular trade is more important than the size of the win or loss. Thus he consistently cuts his profits short while letting his losses run. He also worries more about missing a move in the market by being on the sidelines than about losing by being on the wrong side of a market move; i.e., being in the action is more important than the financial consequences. Participating brokers confirmed that for the majority of the speculators studied, the primary motivation for continuous trading is the recreational utility derived largely from having a market position.

A recent report from the Center for Economic Policy Research (CEPR) has advocated that fixed conversion rates for the start of EMU should be preannounced as soon as possible. The aim of this short paper is to focus on the potential dangers of such a decision. Indeed, the CEPR report propositions are based on the idea that, roughly speaking, fixing a conversion rate in advance should stabilize the exchange rate markets now. We show that this intuition is misleading: knowing the price of an asset at some point in the future has never meant that its current price has a low volatility. Moreover, we perform some simulations to evaluate how volatile exchange rate markets should have been for the past few months if such a rule had been announced. Finally, we provide a constructive proof of what a stabilizing rule should look like.

Recent studies of the Fisher relation have yielded contradictory conclusions on the importance of taxes in determining the long-run response of nominal interest rates to changes in expected inflation. This study uses data on taxable U.S. treasury and tax exempt municipal bond interest rates to shed light on the effects of inflation on nominal interest rates.

The noise trader sentiment model of De Long, Shleifer, Summers, and Waldmann (1990a) is applied to futures markets. The theoretical results predict that overly optimistic (pessimistic) noise traders result in market prices that are greater (less) than fundamental value. Thus, returns can be predicted using the level of noise trader sentiment. The null rational expectations hypothesis is tested against the noise trader alternative using a commercial market sentiment index as a proxy for noise trader sentiment. Fama-MacBeth cross-sectional regressions test if noise traders create a systematic bias in futures prices. The time- series predictability of futures returns using known sentiment levels is tested in a Cumby-Modest market timing framework and a more general causality specification. The empirical results lead to the following conclusions. First, there is no evidence that noise trader sentiment creates a systematic bias in futures prices. Second, predictable market returns using noise trader sentiment is not characteristic of futures markets in general. Third, futures market returns at weekly intervals are characterized by low-order positive autocorrelation with relatively small autoregressive parameters. In those instances where there is evidence of noise trader effects, it is at best limited to isolated markets and particular specifications.

Our research has endeavoured to exploit recent analyses of products and market diversity in terms of the plurality of worlds of production. We show that there are severals ways to be profitable and there is no hierarchie between them. This study is conducted using a sample data of 1354 French companies from the Banque de France Sheet Data Centre that are active in the intermediate goods and business equipment sectors and have fewer than 2.000 employees. We demonstrate that the diversity of products ( generic or dedicated ) and of organisation ( specifics or not specifics assets ) does not create differences of capital structure or profitabilities. In fact this homogeneity express the difficulties for lenders to evaluate firms and appreciate their capacities to manage their own word. That means the capacities to manage the coherence of their action system, i.e. a choice of products and of organisation which allow them to be profitable.

The aim of this paper is to give an overwiev of the behavior of manufacturing firms, in particular the small ones and to go deeper into the conclusion of a previous paper ( Equity and rate of return, ew- fin- 9608001). After some quotes about capital structure and private firms, a comparison of own funds is made between german, french, spanish, italian and austrian manufacturing firms. We can find that french manufacturing firms, for each size studied, are less indebted than their foreign counterparts. Otherwise, french small firms are more profitable and more efficient than the larger ones. We then point out two economic behaviors. The first one depends on growth capacity of the firms and also on their accumulation outlay; the second depends on the intensity of the links with the financial markets, the facilities to obtain lendable funds, all aspects which oblige firms to make high financial profitabilities that can reduce accumulation decisions.

We examine the optimal trading strategy for an investment fund which wishes to maintain two assets in fixed proportions, e.g. 60/40 in stocks and bonds. Transactions costs are assumed to be proportional to the amount of each asset traded. We show that the optimal policy involves a band about the target stock proportion. As long as the actual stock/bond ratio remains inside this band, no trading should occur. If the ratio goes outside the band, trading should be undertaken to move the ratio to the nearest edge of the band. We compute the optimal band and resulting annual turnover and tracking error of the optimal policy, as a function of transactions costs, asset volatility, the target asset mix, and other parameters. We show how changes in transactions costs and other parameters affect the size of the no-trade band, turnover, and tracking error. Compared to a quarterly rebalancing strategy an example demonstrates that the optimal strategy can reduce turnover by almost 50 percent.

The twin problems of hedging and pricing of options in discrete-time markets are analyzed. We consider trading strategies consisting of one stock and one bond. The bond price rises deterministically over time while the stock price can change in several (more than two) ways at each instant of trading. Given such stock price movements, perfect hedging is not possible, and arbitrage arguments alone are not sufficient. We deter- mine hedging and bid and ask prices by balancing expected gain against risk. Using a recent approach of Bouchaud and Sornette, we work out in detail the case where the mean rate of return of the stock differs from that of the bond. We identify a new kind of strategy open to operators that are sufficiently insensitive to risk. We find a candidate for market price of risky options, which reduces to the Black- Scholes prescription when risk can be eliminated. We report on data on stock price movements on the Warsaw Stock Exchange, and show that they are well described by a simple model where prices on each day can either increase, decrease or stay the same. We work out the details of the option pricing and hedging problems in this case.

This paper is a self-contained introduction to the concept and methodology of "value at risk," which is a new tool for measuring an entity's exposure to market risk. We explain the concept of value at risk, and then describe in detail the three methods for computing it: historical simulation; the variance-covariance method; and Monte Carlo or stochastic simulation. We then discuss the advantages and disadvantages of the three methods for computing value at risk. Finally, we briefly describe some alternative measures of market risk.

Within the framework of Diamond-Dybvig (1983), the optimal (run free) outcome is shown to be the unique forward induction equilibrium. In a version of the model that posits Bertrand competition among banks, there are sequential equilibria that imply positive profits. However, the zero-profit contract is supported as the unique equilibrium outcome if the agents' beliefs are restricted to the space of beliefs consistent with the forward induction refinement.

I study equilibrium selection by an evolutionary process in an environment with multiple equilibria, one of which involves a banking panic. The analysis is built on a repeated version of the Diamond-Dybvig (1983) model. The optimal equilibrium is uniquely selected if it is also ‘risk dominant’. When there are multiple banks, the probability of observing a panic increases as the size of the banks decreases. Local interaction generates contagion effects that allow a bank run to spread first among banks in the same geographic location and then throughout the population.

Since early 1994, there have been signs of an upturn in economic activity . The strength and scope of the recovery depend to a large extent on the ability of companies to exploit their competitiveness, which is dependent on the decisions they take today, particularly where both tangible and intangible investments are concerned. The aim of this article is to identify specific types of economic behaviour and to relate them to companies' investment, and particularly intangible investment, decisions. It is first of all necessary to define competitiveness and to suggest a measurement indicator suited to aggregated accounting data. The link between competitiveness and profitability will be specified and the diversity of the companies will then be highlighted.

We study the problem of illiquidity that afflicts the stocks listed on the Bombay Stock Exchange (B.S.E.). Trading on a regular basis is concentrated in only a few of the listed stocks. We examine this issue by empirically looking at the characteristics of firms leading to differential levels of trading frequency and also, the resultant effect on average returns. Based on the study of a random sample of 250 firms over the five year period - 1989 to 1993, we find evidence in favor of a liquidity premium for stocks on the B.S.E. Also, we find trading frequency is positively related to number of shareholders and shares outstanding. In addition, the ownership structure seems to matter, with concentration in the hands of insiders and government bodies having a deleterious effect on liquidity.

In India there existed, until recently, a form of highly leveraged margin trading called the Badla system, for certain stocks categorized as group A stocks. In March of 1994, the Securities and Exchange Board of India (SEBI) has effectively banned the facility blaming it for causing "excessive speculation". We study the effect of badla trading on stock return volatility by comparing the daily data from 1992 for group A and a matched sample of group B stocks. After controlling for other factors such as trading frequency, the average price level and the market capitalization of the firms, we find that the residual variance is actually lower for the group A stocks. Also, variance ratio tests indicate, that after accounting for other factors, no differences in the magnitude of price reversals (serial correlation) for both groups of stocks. Hence, SEBI's decision does not seem justified on economic grounds.

In this article, we study conditional heteroscedasticity in a market index on the Bombay Stock Exchange, from April 1979 to March 1995. We find strong evidence of heteroscedasticity in daily, weekly and monthly returns. The conditional variance of all three data series seem best approximated by a GARCH(1,1) model. The GARCH parameter estimates at all data frequencies exhibit strong persistence in variance. In the case of monthly returns, we find there is seasonality in the volatility, and there is one regime shift in the level of unconditional variance of the data. Remarkably enough, after controlling for these, monthly returns are homoscedastic, and there is no persistence. Both, the regime shift and the seasonality, have clear economic interpretations. The regime shift appears in March 1985, and is associated with a sharp turn towards market-oriented economic policies - among other things, this led to an enormous expansion of the domestic IPO market and secondary market trading volumes. The seasonality in the post-March-1985 period is characterised by enhanced volatility associated with each federal budget announcement in end-February. The results with weekly and daily data are not as drastic -- while strong evidence of the regime shift and of seasonality is found in daily and weekly data, even after controlling for these, returns are still ARCH, and still exhibit a fair degree of persistence. Finally, we use our volatility models to test whether the market prices the observed heteroscedasticity using GARCH-in-mean models. We are unable to reject the null that higher risk is not priced. We offer qualitative arguments suggesting reasons for this behaviour and conjecture that this may change in the near future.

This article studies India's vibrant IPO market, via a dataset of the 2056 IPOs which took place in the last 4.5 years. We study the overall underpricing, the delay between issue date and listing date, the time- series of monthly volume of IPO issues and average underpricing in a given month, the cross-section of underpricing across companies, the post-listing trading frequency, the long-run returns to new listings, and price discovery by the market shortly after first listing.

On 12 March 1994, SEBI imposed new norms on trading in the Bombay Stock Exchange, and the effective consequence of this has been an elimination of {\em badla}, a form of forward trading. Without badla, the role of speculative traders on the BSE is diminished. This paper sets out to measure the impact of this elimination of speculative trading upon volatility on the BSE. We explore, and criticise, a variety of different methods of arriving at a conclusion on this question, and present an estimation strategy which exploits the unique opportunity to view this episode as a natural experiment. Our examination of daily unsystematic risk, which takes the value of 3\% in our sample on average, reveals that badla diminishes it by roughly 0.25 percentage points. The statistical significance of this estimate is weak, especially in the light of a qualitative argument suggesting that this estimate is biased upwards. Working with weekly returns data, badla seems to have no impact upon unsystematic risk. On the subject of market efficiency, we find that badla is slightly beneficial for short--horizon market efficiency: the non-forecastability of daily returns of A companies has worsened in the year following 12 March 1994. This effect is concentrated in the short horizon; the degree of forecastability of weekly returns has actually diminished slightly in the year after 12 March 1994.

This article relates the experience of abnormal returns on the Bombay Stock Exchange surrounding the pricing date of GDR issues by Indian firms. On 15 May 1994, empirical evidence suggesting that such abnormal returns do exist was released into the information set of agents in the financial industry. Today, as many GDR issues have taken place after 15 May 1994 as had taken place before, and we can measure how this mispricing has changed. We find that the extent of mispricing has dropped sharply: the highest point in the average cumulative returns in excess of the market index over the weeks preceding the pricing date have dropped from 18.9\% for the 20 GDR issues before 15 May 1994 to 6.9\% for the 26 GDR issues after this date. This reduction in the extent of mispricing is consistent with our understanding of arbitrage by rational agents in financial markets.

In the companion paper on empirical regularities of India's IPO market, we found a high degree of underpricing. IPO underpricing is not healthy -- it involves penalising unlisted companies with a high cost of capital; this is unlikely to be a criterion along which the efficiency of resource allocation is maximised. In this paper, we propose four policy alternatives, which are primarily (though not exclusively) aimed at decreasing the extent of IPO underpricing: 1. We propose improvements to the quality of information disclosure at the time of a public issue. 2. We propose giving firms greater freedom to choose the offer price close to the issue date. 3. We propose an auction--based strategy for the primary market. 4. We offer a way to legitimise the gray market and bring it within the fold of the institutional framework governing financial markets of the country.

Recent research has focused on studying the patterns in the digits of closely followed stock market indeces (see, \eg, Ley and Varian (1994) and Koedijk and Stork (1994)). In this paper, we find that the series of one-day returns on the Dow-Jones Industrial Average Index (\djia) and the Standard and Poor's Index (\sp) reasonably agrees with Benford's law and, therefore, belongs to the family of {\it anomalous\/} or {\it outlaw\/} numbers.

The study of the relation between risk and return is an important topic forinvestors in financial assets, which is the reason why many researchers have tackled it. It isonly natural for an investor with aversion for risk, who undertakes a higher risk investment,mare to expect be rewarded accordingly, that is to achieve higher return rates. The researchconducted on various stock markets had contradictory results, which means that the existenceof such a connection is not certain on all stock markets. According to a new hypothesis,tackled by the latest studies, the aversion for risk of rational investors may be related to thestages of the business cycles. This paper deals with the connection between expected returnand volatility at Bucharest Stock Exchange, by analyzing the return and volatility of the BETindex portfolio. In order to assess this relation, we employed heteroskedastic autoregressivemodels. The study was conducted between January 2000 and April 2011, as well as duringtwo sub-periods determined by different business cycle phases: economic growth andrecession. The results revealed significant differences between the whole analyzed period andthe economic growth and recession sub-periods. By studying BSE return throughout theanalyzed period, we conclude that there is no relationship between expected return and risk,whereas volatility is asymmetric. Actually, one may witness a relation between return andrisk, as well as a non-asymmetric response of volatility to shocks during economic growth,and no risk-return relationship and asymmetric volatility during economic recession. Also,results have shown a positive relationship between return and volatility during economicgrowth, and a negative relationship between the same during economic recession.

We present a new method, inspired by the bootstrap, whose goal it is to determine the quality and reliability of a neural network predictor. Our method leads to more robust forecasting along with a large amount of statistical information on forecast performance that we exploit. We exhibit the method in the context of multi-variate time series prediction on financial data from the New York Stock Exchange. It turns out that the variation due to different resamplings (i.e., splits between training, cross-validation, and test sets) is significantly larger than the variation due to different network conditions (such as architecture and initial weights). Furthermore, this method allows us to forecast a probability distribution, as opposed to the traditional case of just a single value at each time step. We demonstrate this on a strictly held-out test set that includes the 1987 stock market crash. We also compare the performance of the class of neural networks to identically bootstrapped linear models.

pricing. A factor subspace contains the market portfolio and is such that every marketed contingent claim is second-order stochastically dominated by a claim from the factor subspace. Conditions are given for the existence of equilibrium, and it is shown how APT and CAPM can be interpreted in the framework of the paper. If sufficiently many call options on the market portfolio are traded, then the space spanned by these options can be used as the factor subspace. We consider markets in which a collection of financial assets are traded. The collection may be finite or infinite. Markets are frictionless, and short-sales of assets are permitted. Asset payoffs are random variables which are elements of a space of contingent claims. By forming portfolios of the marketed assets, payoffs in a certain linear subspace of the space of all contingent claims can be attained. We call this subspace a space of marketed claims. We say that a closed subspace of the space of marketed claims is a factor subspace if two conditions are satisfied: first, the market portfolio payoff (i.e. the payoff of an aggregate endowment of portfolios per capita) belongs to this subspace; second, every marketed contingent claim is dominated in the sense of second-order stochastic dominance by some contingent claim in the factor subspace. We demonstrate that for each asset market economy, there is a well-defined minimal factor subspace in the sense that no proper subspace of it can be a factor subspace. If markets are complete, i.e., if a full set of Arrow securities are traded, then the price of any given asset can be expressed in terms of prices of Arrow securities or state prices. Breeden and Litzenberger (1978) have shown that state prices can be replaced by the values of options. Thus in a complete market asset prices are determined either by state prices or call options. It is established in this paper that these ideas and methods are applicable to asset pricing theories even when markets are incomplete. Making use of the argument of second-order stochastic dominance, we show that every constrained Pareto optimal portfolio allocation consists exclusively of portfolios which generate the factor subspace. The same holds for an equilibrium portfolio allocation. Thus, for an economy with a factor subspace, only a partial set of Arrow securities which is large enough to generate the factor subspace is required to price assets. This paper establishes that there exists an equilibrium in which the price of a portfolio equals the price of the dominating portfolio with the same expected return in the factor subspace. Since the dominating

We present a dynamical theory of asset price bubbles that exhibits the appearance of bubbles and their subsequent crashes. We show that when speculative trends dominate over fundamental beliefs, bubbles form, leading to the growth of asset prices away from their fundamental value. This growth makes the system increasingly susceptible to any exogenous shock, thus eventually precipitating a crash. We also present computer experiments which in their aggregate behavior confirm the predictions of the theory., Postscript file with 21 pages. Comments to youssefm, huberman, or hogg@parc.xerox.com