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We develop a model of financially constrained arbitrage, and use it to study the dynamics of arbitrage capital, liquidity, and asset prices. Arbitrageurs exploit price discrepancies between assets traded in segmented markets, and in doing so provide liquidity to investors. A collateral constraint limits their positions as a function of capital. We show that the dynamics of arbitrage activity are self-correcting: following a shock that depletes arbitrage capital, profitability increases, and this allows capital to be gradually replenished. Spreads increase more and recover faster for more volatile trades, although arbitrageurs cut their positions in these trades the least. When arbitrage capital is more mobile across markets, liquidity in each market generally becomes less volatile, but the reverse may hold for aggregate liquidity because of mobility-induced contagion.

We present a model of a financial market where some traders are "cursed" when investing in a risky asset, failing to fully appreciate what prices convey about others' private information. Markets comprising cursed traders generate more trade than those comprising rationals; mixed markets can generate even more trade because rationals exploit return predictability caused by cursed. Per-trader volume in cursed markets increases with market size; volume may instead disappear when traders infer others' information from prices but dismiss it as noisier than their own. Public-information revelation raises rational and"dismissive" volume, but lowers cursed volume given moderate non-informational trading motives.

It is well known that rational bubbles can be sustained in balanced growth path of a deterministic economy when the return to capital r is equal to the growth rate g. When there is a lack of stores of value, bubbles can implement an e¢ cient allocation. This paper considers a world where r áuctuates over time due to shocks to the marginal productivity of capital. Then, bubbles further e¢ ciency, though they cannot implement Örst best. While bubbles can only be sustained when r = g in a deterministic economy, r > g "on average" in a stochastic economy. Fiscal policy improves welfare by adding an extra asset. Where only the elderly contribute to shifting resources between investment and consumption in a bubbly economy, Öscal policy allows part of that burden to be shifted to the young. Contrary to common wisdom, trade in bubbly assets implements intergenerational transfers, while Öscal policy implements intragenerational transfers. Hence, while bubbles and Öscal policy are perfect substitutes in the deterministic economy, Öscal policy dominates bubbles in a stochastic economy. For plausible parameter values, a higher degree of dynamic ine¢ ciency should lead to a higher sovereign debt.

Obsession with short-term performance against market cap benchmarks preordains the dysfunctionality of asset markets. The problems start when trustees hire fund managers to outperform benchmark indexes subject to limits on annual divergence. For multi-asset portfolios the benchmark is generally the performance of peer group funds, also based on market cap. In the absence of formal instructions, asset managers, as well as off-the-peg mutual funds, are still keen to demonstrate their ability against the competition in the short run. If securities markets were efficiently priced in the sense of reflecting best estimates of fundamental value, there would be no problem in using market cap benchmarks. But the terms under which most professional investment is handled ensure that markets are not efficient. Benchmarking causes, first, the inversion of the relationship between risk and return so that high volatile securities and asset classes offer lower returns than low volatile ones. Second, it fosters the pursuit of momentum strategies which then earn profits at the expense of benchmarked funds. The paper explains how these problems arise using rational models of asset mispricing and proposes an incentive-based solution.

The euro crisis was fueled by the diabolic loop between sovereign risk and bank risk, coupled with cross-border flight-to-safety capital flows. European Safe Bonds (ESBies), a union-wide safe asset without joint liability, would help to resolve these problems. We make three contributions. First, numerical simulations show that ESBies would be at least as safe as German bunds and approximately double the supply of euro safe assets when protected by a 30%-thick junior tranche. Second, a model shows how, when and why the two features of ESBies - diversification and seniority - can weaken the diabolic loop and its diffusion across countries. Third, we propose a step-by-step guide on how to create ESBies, starting with limited issuance by public or private-sector entities.

We develop a model of financially constrained arbitrage, and use it to study the dynamics of arbitrage capital, liquidity, and asset prices. Arbitrageurs exploit price discrepancies between assets traded in segmented markets, and in doing so provide liquidity to investors. A collateral constraint limits their positions as a function of capital. We show that the dynamics of arbitrage activity are self-correcting: following a shock that depletes arbitrage capital, profitability increases, and this allows capital to be gradually replenished. Spreads increase more and recover faster for more volatile trades, although arbitrageurs cut their positions in these trades the least. When arbitrage capital is more mobile across markets, liquidity in each market generally becomes less volatile, but the reverse may hold for aggregate liquidity because of mobility-induced contagion.

We develop a dynamic model of liquidity provision, in which hedgers can trade multiple risky assets with arbitrageurs. We compute the equilibrium in closed form when arbitrageurs’ utility over consumption is logarithmic or risk-neutral with a non-negativity constraint. Liquidity is increasing in arbitrageur wealth, while asset volatilities, correlations, and expected returns are hump-shaped. Liquidity is a priced risk factor: assets that suffer the most when liquidity decreases, e.g., those with volatile cashflows or in high supply by hedgers, offer the highest expected returns. When hedging needs are strong, arbitrageurs can choose to provide less liquidity even though liquidity provision is more profitable.

In this paper we survey the theoretical and empirical literature on market liquidity. We organize both literatures around three basic questions: (a) how to measure illiquidity, (b) how illiquidity relates to underlying market imperfections and other asset characteristics, and (c) how illiquidity affects expected asset returns. Using a unified model from Vayanos and Wang (2010), we survey theoretical work on six main imperfections: participation costs, transaction costs, asymmetric information, imperfect competition, funding constraints, and search-and for each imperfection we address the three basic questions within that model. We review the empirical literature through the lens of the theory, using the theory to both interpret existing results and suggest new tests and analysis.

We propose a rational theory of momentum and reversal based on delegated portfolio management. A competitive investor can invest through an index fund or an active fund run by a manager with unknown ability. Following a negative cashflow shock to assets held by the active fund, the investor updates negatively about the manager’s ability and migrates to the index fund. While prices of assets held by the active fund drop in anticipation of the investor’s outflows, the drop is expected to continue, leading to momentum. Because outflows push prices below fundamental values, expected returns eventually rise, leading to reversal. Fund flows generate comovement and lead-lag effects, with predictability being stronger for assets with high idiosyncratic risk. We derive explicit solutions for asset prices, within a continuous-time normal-linear equilibrium.

We estimate structurally a model of the term structure of interest rates that is consistent with no arbitrage but allows for demand pressures. The term structure in our model is determined through the interaction of risk-averse arbitrageurs and preferred-habitat investors with preferences for specific maturities. The model is estimated on US real rates during the 2000s and allows for two factors: one corresponding to the short rate and one to preferred-habitat demand. We find that the puzzling drop in long rates during 2004-05 (Greenspan conundrum) is driven by the demand factor, which in turn is correlated with purchases of long-term bonds by foreign officials. For example, foreign purchases in July 2004 appear to have lowered the 10-year rate by about 100 basis points. Foreign purchases have larger effects following periods when arbitrageurs have lost money.

We study flows between investment funds and their effects on asset prices in a simple twoperiod version of Vayanos and Woolley (2010, VW). As in VW, flows cause assets to comove in ways unrelated to fundamentals, affect assets with high idiosyncratic risk the most, and raise the expected returns of funds experiencing outflows. We sketch how adding periods can generate other results of VW such as momentum, reversal, amplification, and commercial-risk management. We also extend the VW framework to study how index redefinitions affect the price level and the extent of comovement. This is a revised version of Working Paper Series No 15, FMG Discussion Paper No 662.

Almost 20 Greek academic economists from renowned universities in Europe and the US have prepared a one-page statement regarding the Greek crisis. In their statement the economic experts call upon the Greek public to accept the economic program of structural reforms, privatization, efficient tax collection, and shrinking of the public sector proposed and financed by the EU partners and the IMF. Among the signatories are this year's Nobel Prize winner Christopher Pissarides and Michalis Haliassos, Director of the Center for Financial Studies and Professor for Macroeconomics and Finance at the House of Finance.

We survey theoretical developments in the literature on the limits of arbitrage. This literature investigates how costs faced by arbitrageurs can prevent them from eliminating mispricings and providing liquidity to other investors. Research in this area is currently evolving into a broader agenda emphasizing the role of financial institutions and agency frictions for asset prices. This research has the potential to explain so-called "market anomalies" and inform welfare and policy debates about asset markets. We begin with examples of demand shocks that generate mispricings, arguing that they can stem from behavioral or from institutional considerations. We next survey, and nest within a simple model, the following costs faced by arbitrageurs: (i) risk, both fundamental and non-fundamental, (ii) short-selling costs, (iii) leverage and margin constraints, and (iv) constraints on equity capital. We finally discuss implications for welfare and policy, and suggest directions for future research.

We model the term structure of interest rates as resulting from the interaction between investor clienteles with preferences for specific maturities and risk-averse arbitrageurs. Because arbitrageurs are risk averse, shocks to clienteles’ demand for bonds affect the term structure— and constitute an additional determinant of bond prices to current and expected future short rates. At the same time, because arbitrageurs render the term structure arbitrage-free, demand effects satisfy no-arbitrage restrictions and can be quite different from the underlying shocks. We show that the preferred-habitat view of the term structure generates a rich set of implications for bond risk premia, the effects of demand shocks and of shocks to short-rate expectations, the economic role of carry trades, and the transmission of monetary policy.

We examine how liquidity and asset prices are affected by the following market imperfections: asymmetric information, participation costs, transaction costs, leverage constraints, non-competitive behavior and search. Our model has three periods: agents are identical in the first, become heterogeneous and trade in the second, and consume asset payoffs in the third. We examine how imperfections in the second period affect different measures of illiquidity, as well as asset prices in the first period. Besides nesting multiple imperfections in a single model, we derive new results on the effects of each imperfection. Our results imply, in particular, that imperfections do not always raise expected returns, and can influence common measures of illiquidity in opposite directions.

We examine empirically how the maturity structure of government debt affects bond yields and excess returns. Our analysis is based on a theoretical model of preferred habitat in which clienteles with strong preferences for specific maturities trade with arbitrageurs. Consistent with the model, we find that (i) the supply of long- relative to short-term bonds is positively related to the term spread, (ii) supply predicts positively long-term bonds’ excess returns even after controlling for the term spread and the Cochrane-Piazzesi factor, (iii) the effects of supply are stronger for longer maturities, and (iv) following periods when arbitrageurs have lost money, both supply and the term spread are stronger predictors of excess returns.

We develop a model of the gambler's fallacy (the mistaken belief that random sequences should exhibit systematic reversals). We show that an individual who holds this belief and observes a sequence of signals can exaggerate the magnitude of changes in an underlying state but underestimate their duration. When the state is constant, and so signals are i.i.d., the individual can predict that long streaks of similar signals will continue { a hot-hand fallacy. When signals are serially correlated, the individual typically under-reacts to short streaks, over-reacts to longer ones, and under-reacts to very long ones. We explore several applications, showing, for example, that investors may move assets too much in and out of mutual funds, and exaggerate the value of financial information and expertise.

We study market efficiency in an infinite-horizon model with a monopolistic insider. The insider can trade with a competitive market maker and noise traders, and observes privately the expected growth rate of asset dividends. In the absence of the insider, this information would be reflected in prices only after a long series of dividend observations. The insider chooses, however, to reveal the information very quickly, within a time converging to zero as the market approaches continuous trading. Although the market converges to strong-form efficiency, the insider's profits do not converge to zero.

We propose a model in which assets with identical cash flows can trade at different prices. Agents enter into an infinite-horizon, steady-state market to establish long or short positions. Both the spot and the asset-lending market operate through search. Short-sellers can endogenously concentrate in one asset because of search externalities and the constraint that they must deliver the asset they borrowed. As a result, that asset enjoys both greater liquidity, measured by search times, and a higher lending fee ("specialness"). Liquidity and specialness translate into price premia that are consistent with no-arbitrage. We derive closed-form solutions for small frictions, and can generate price differentials in line with observed on-the-run premia.

We develop a search-based model of asset trading, in which investors of different horizons can invest in two identical assets. The asset markets are partially segmented: buyers can search for only one asset, but can decide which one. We show that there exists a "clientele" equilibrium where one market has more buyers and sellers, lower search times, higher trading volume, higher prices, and short-horizon investors. This equilibrium dominates the ones where the two markets are identical, implying that the concentration of liquidity in one asset is socially desirable. At the same time, too many buyers decide to search for the liquid asset.

We propose a dynamic equilibrium model of a multi-asset market with stochastic volatility and transaction costs. Our key assumption is that investors are fund managers, subject to withdrawals when fund performance falls below a threshold. This generates a preference for liquidity that is time-varying and increasing with volatility. We show that during volatile times, assets' liquidity premia increase, investors become more risk averse, assets become more negatively correlated with volatility, assets' pairwise correlations can increase, and illiquid assets' market betas increase. Moreover, an unconditional CAPM can understate the risk of illiquid assets because these assets become riskier when investors are the most risk averse.