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A long-standing puzzle is how overconfidence can persist in settings characterized by repeated feedback. This paper studies managers who participate repeatedly in a high-powered tournament incentive system, learning relative performance each time. Using reduced form and structural methods we find that (i) managers make over-confident predictions about future performance; (ii) managers have overly positive memories of past performance; (iii) the two phenomena are linked at an individual level. Our results are consistent with models of motivated beliefs in which individuals are motivated to distort memories of feedback and preserve unrealistic expectations. (JEL D82, D83, J33, L25, L81, M52, M54)

This article studies the relationship between patience and comparative development through a combination of reduced-form analyses and model estimations. Based on a globally representative dataset on time preference in 76 countries, we document two sets of stylized facts. First, patience is strongly correlated with per capita income and the accumulation of physical capital, human capital, and productivity. These correlations hold across countries, sub-national regions, and individuals. Second, the magnitude of the patience elasticity strongly increases in the level of aggregation. To provide an interpretive lens for these patterns, we analyse an overlapping generations model in which savings and education decisions are endogenous to patience, aggregate production is characterized by capital-skill complementarities, and productivity implicitly depends on patience through a human capital externality. In our model estimations, general equilibrium effects alone account for a non-trivial share of the observed amplification effects, and an extension to human capital externalities can quantitatively match the empirical evidence.

Background Forest and nonforest ecosystems of the western United States are experiencing major transformations in response to land-use change, climate warming, and their interactive effects with wildland fire. Some ecosystems are transitioning to persistent alternative types, hereafter called “vegetation type conversion” (VTC). VTC is one of the most pressing management issues in the southwestern US, yet current strategies to intervene and address change often use trial-and-error approaches devised after the fact. To better understand how to manage VTC, we gathered managers, scientists, and practitioners from across the southwestern US to collect their experiences with VTC challenges, management responses, and outcomes. Results Participants in two workshops provided 11 descriptive case studies and 61 examples of VTC from their own field observations. These experiences demonstrate the extent and complexity of ecological reorganization across the region. High-severity fire was the predominant driver of VTC in semi-arid coniferous forests. By a large margin, these forests converted to shrubland, with fewer conversions to native or non-native herbaceous communities. Chaparral and sagebrush areas nearly always converted to non-native grasses through interactions among land use, climate, and fire. Management interventions in VTC areas most often attempted to reverse changes, although we found that these efforts cover only a small portion of high-severity burn areas undergoing VTC. Some areas incurred long (>10 years) observational periods prior to initiating interventions. Efforts to facilitate VTC were rare, but could cover large spatial areas. Conclusions Our findings underscore that type conversion is a common outcome of high-severity wildland fire in the southwestern US. Ecosystem managers are frontline observers of these far-reaching and potentially persistent changes, making their experiences valuable in further developing intervention strategies and research agendas. As its drivers increase with climate change, VTC appears increasingly likely in many ecological contexts and may require management paradigms to transition as well. Approaches to VTC potentially include developing new models of desired conditions, the use of experimentation by managers, and broader implementation of adaptive management strategies. Continuing to support and develop science-manager partnerships and peer learning groups will help to shape our response to ongoing rapid ecological transformations.

Background/objective Financial incentives can improve initial weight loss; we examined whether financial incentives can improve weight loss maintenance. Subjects/methods Participants aged 30–80 years who lost at least 5 kg during the first 4–6 months in a nationally available commercial weight loss program were recruited via the internet into a three-arm randomized trial of two types of financial incentives versus active control during months 1–6 (Phase I) followed by passive monitoring during months 7–12 (Phase II). Interventions were daily self-weighing and text messaging feedback alone (control) or combined with a lottery-based incentive or a direct incentive. The primary outcome was weight change 6 months after initial weight loss. Secondary outcomes included weight change 12 months after initial weight loss (6 months after cessation of maintenance intervention), and self-reported physical activity and eating behaviors. Results Of 191 participants randomized, the mean age was 49.0 (SD = 10.5) years and weight loss prior to randomization was 11.4 (4.7) kg; 92% were women and 89% were White. Mean weight changes during the next 6 months (Phase I) were: lottery −3.0 (5.8) kg; direct −2.8 (5.8) kg; and control −1.4 (5.8) kg (all pairwise comparisons p > 0.1). Weight changes through the end of 12 months post-weight loss (Phase II) were: lottery −1.8 (10.5) kg; direct −0.7 (10.7) kg; and control −0.3 (9.4) kg (all pairwise comparisons p > 0.1). The percentages of participants who maintained their weight loss (defined as gaining ≤1.36 kg) were: lottery 79%, direct 76%, and control 67% at 6 months and lottery 66%, direct 62%, and control 59% at 12 months (all pairwise comparisons p > 0.1). At 6 and 12 months after initial weight loss, changes in self-reported physical activity or eating behaviors did not differ across arms. Conclusions Compared with the active control of daily texting based on daily home weighing, lottery-based and direct monetary incentives provided no additional benefit for weight loss maintenance.

Background Obesity continues to be a serious public health challenge. Rates are increasing worldwide, with nearly 70% of the US adults overweight or obese, leading to increased clinical and economic burden. While successful approaches for achieving weight loss have been identified, techniques for long-term maintenance of initial weight loss have largely been unsuccessful. Financial incentive interventions have been shown in several settings to be successful in motivating participants to adopt healthy behaviors. Purpose Keep It Off is a three-arm randomized controlled trial that compares the efficacy of a lottery-based incentive, traditional direct payment incentive, and control of daily feedback without any incentive for weight-loss maintenance. This design allows comparison of a traditional direct payment incentive with one based on behavioral economic principles that consider the underlying psychology of decision-making. Methods Participants were randomized in a 2:1 ratio for each active arm relative to control, with a targeted 188 participants in total. Eligible participants were those aged 30–80 who lost at least 11 lb (5 kg) during the first 4 months of participation in Weight Watchers, a national weight-loss program, with whom we partnered. The interventions lasted 6 months (Phase I); participants were followed for an additional 6 months without intervention (Phase II). The primary outcome is weight change from baseline to the end of Phase I, with the change at the end of Phase II a key secondary endpoint. Keep It Off is a pragmatic trial that recruited, consented, enrolled, and followed patients electronically. Participants were provided a wireless weight scale that electronically transmitted daily self-monitored weights. Weights were verified every 3 months at a Weight Watchers center local to the participant and electronically transmitted. Results Using the study web-based platform, we integrated recruitment, enrollment, and follow-up procedures into a digital platform that required little staff effort to implement and manage. We randomized 191 participants in less than 1 year. We describe the design of Keep It Off and implementation of enrollment. Lessons Learned We demonstrated that our pragmatic design was successful in rapid accrual of participants in a trial of interventions to maintain weight loss. Limitations Despite the nationwide reach of Weight Watchers, the generalizability of study findings may be limited by the characteristics of its members. The interventions under study are appropriate for settings where an entity, such as an employer or health insurance company, could offer them as a benefit. Conclusions Keep It Off was implemented and conducted with minimal staff effort. This study has the potential to identify a practical and effective weight-loss maintenance strategy.

This article studies the global variation in economic preferences. For this purpose, we present the Global Preference Survey (GPS), an experimentally validated survey data set of time preference, risk preference, positive and negative reciprocity, altruism, and trust from 80,000 people in 76 countries. The data reveal substantial heterogeneity in preferences across countries, but even larger within-country heterogeneity. Across individuals, preferences vary with age, gender, and cognitive ability, yet these relationships appear partly country specific. At the country level, the data reveal correlations between preferences and biogeo-graphic and cultural variables, such as agricultural suitability, language structure, and religion. Variation in preferences is also correlated with economic outcomes and behaviors. Within countries and subnational regions, preferences are linked to individual savings decisions, labormarket choices, and prosocial behaviors. Across countries, preferences vary with aggregate outcomes ranging from per capita income, to entrepreneurial activities, to the frequency of armed conflicts.

OBJECTIVE Healthy pancreatic β-cells secrete the hormones insulin and amylin in a fixed ratio. Both hormones are lacking in type 1 diabetes, and postprandial glucose control using insulin therapy alone is difficult. This study tested the pharmacodynamic effects of the amylin analog pramlintide and insulin delivered in a fixed ratio over a 24-h period. RESEARCH DESIGN AND METHODS Patients with type 1 diabetes were stabilized on insulin pump therapy with insulin lispro before a randomized, single-masked, two-way crossover, 24-h inpatient study in which regular human insulin was administered with pramlintide or placebo using separate infusion pumps in a fixed ratio (9 μg/unit). Meal content and timing and patient-specific insulin doses were the same with each treatment. The primary outcome measure was change in mean glucose by continuous glucose monitoring (CGM). Profiles of laboratory-measured glucose, insulin, glucagon, and triglycerides were also compared. RESULTS Mean 24-h glucose measured by CGM was lower with pramlintide versus placebo (8.5 vs. 9.7 mmol/L, respectively; P = 0.012) due to a marked reduction of postprandial increments. Glycemic variability was reduced, and postprandial glucagon and triglycerides were also lower with pramlintide versus placebo. Gastrointestinal side effects were more frequent during use of pramlintide; no major hypoglycemic events occurred with pramlintide or placebo. CONCLUSIONS Coadministration of fixed-ratio pramlintide and regular human insulin for 24 h improved postprandial hyperglycemia and glycemic variability in patients with type 1 diabetes. Longer studies including dose titration under daily conditions are needed to determine whether this regimen could provide long-term improvement of glycemic control.

Understanding the nature of trust has substantial implications for thinking about the economics of law. In this chapter the authors consider the interaction between laws and trust. They pursue this inquiry by looking at the growth of the behavioral economics and organizational economics literatures. After describing a model of trust, the authors review results on the relationship between trust and growth from the development and macroeconomics empirical literatures. The chapter then turns to evidence from experiments that shed light on mechanisms that may link trust and the law and help us understand why in some circumstances they may be complementary and in others substitutes. The authors draw some preliminary conclusions about the factors that might contribute to explaining complementarity of trust and the law at the macro level. The chapter ends with a discussion of some specific laws, and how these interact with trust.

Trust affects almost all human relationships – in families, organizations, markets and politics. However, identifying the conditions under which trust, defined as people’s beliefs in the trustworthiness of others, has a causal effect on the efficiency of human interactions has proven to be difficult. We show experimentally and theoretically that trust indeed has a causal effect. The duration of the effect depends, however, on whether initial trust variations are supported by multiple equilibria. We study a repeated principal-agent game with multiple equilibria and document empirically that an efficient equilibrium is selected if principals believe that agents are trustworthy, while players coordinate on an inefficient equilibrium if principals believe that agents are untrustworthy. Yet, if we change the institutional environment such that there is a unique equilibrium, initial variations in trust have short-run effects only. Moreover, if we weaken contract enforcement in the latter environment, exogenous variations in trust do not even have a short-run effect. The institutional environment thus appears to be key for whether trust has causal effects and whether the effects are transient or persistent.

This article investigates how risk attitudes change over the life course. We study the age trajectory of risk attitudes all the way from early adulthood until old age, in large representative panel data sets from the Netherlands and Germany. Age patterns are generally difficult to identify separately from cohort or calendar period effects. We achieve identification by replacing calendar period indicators with controls for the specific underlying factors that may change risk attitudes across periods. The main result is that willingness to take risks decreases over the life course, linearly until approximately age 65 after which the slope becomes flatter.

This paper examines heterogeneity in time discounting among a representative sample of elderly Americans, as well as its role in explaining key economic behaviors at older ages. We show how older Americans evaluate simple (hypothetical) inter-temporal choices in which payments today are compared with payments in the future. Using the indicators derived from this measure, we then demonstrate that differences in discounting patterns are associated with characteristics of particular importance in elderly populations. For example, cognitive deficits are associated with greater impatience, whereas bequest motives are associated with less impatience. We then relate our discounting measure to key economic outcomes and find that impatience is associated with lower wealth, fewer investments in health, and less planning for end of life care.

We performed an assay to test the ability of different E. coli strains to survive inside amoebal cells after ingestion. In the assay we incubated bacteria together with cells of Dictyostelium discoideum for six hours. After co-incubation most of the uningested bacteria were removed by centrifugation and the remaining uningested bacteria were killed by gentamicin. Gentamicin is used because it does not penetrate into eukaryotic cells allowing the ingested bacteria to survive the antibiotic treatment, whereas bacteria outside the amoebal cells are killed.

This article provides evidence that involuntary unemployment, and the segmentation of labour markets into firms offering "good" and "bad" jobs, may both arise as a consequence of contractual incompleteness. We provide a simple model that illustrates how unemployment and market segmentation may jointly emerge as part of a market equilibrium in environments where work effort is not third-party verifiable. Using experimental labour markets that differ only in the verifiability of effort, we demonstrate empirically that contractual incompleteness can cause unemployment and segmentation. Our data are also consistent with the key channels through which the model explains the emergence of both phenomena. Copyright 2014, Oxford University Press.

The Great Oxidation Event resulted in integration of soft metals in a wide range of biochemical processes including, in our opinion, killing of bacteria by protozoa. Compared to pressure from anthropologic copper contamination, little is known on impacts of protozoan predation on maintenance of copper resistance determinants in bacteria. To evaluate the role of copper and other soft metals in predatory mechanisms of protozoa, we examined survival of bacteria mutated in different transition metal efflux or uptake systems in the social amoeba Dictyostelium discoideum. Our data demonstrated a strong correlation between the presence of copper/zinc efflux as well as iron/manganese uptake, and bacterial survival in amoebae. The growth of protozoa, in turn, was dependent on bacterial copper sensitivity. The phagocytosis of bacteria induced upregulation of Dictyostelium genes encoding the copper uptake transporter p80 and a triad of Cu(I)-translocating P

A key open question for theories of reference-dependent preferences is: what determines the reference point? One candidate is expectations: what people expect could affect how they feel about what actually occurs. In a real-effort experiment, we manipulate the rational expectations of subjects and check whether this manipulation influences their effort provision. We find that effort provision is significantly different between treatments in the way predicted by models of expectation-based, reference-dependent preferences: if expectations are high, subjects work longer and earn more money than if expectations are low. (JEL D12, D84, J22)

This research project evaluates the extent of heterogeneity in time discounting among elderly Americans, as well as its role in explaining older peoples’ key behaviors. We first show how older Americans evaluate simple (hypothetical) intertemporal choices in which payments now are compared with payments in the future. This adds to the literature on time horizon experiments by focusing on a nationally representative sample of persons age 70+. Using the indicators derived from this experiment, we show how differences in discounting patterns are associated with characteristics of particular importance in elderly populations, such as serious health and mental conditions. We then relate our discounting measure to key outcome variables including wealth, the timing of retirement, investments in health, and decisions about end-of-life care.

Economists are increasingly interested in how group membership affects individual behavior. The standard method assigns individuals to “minimal” groups, i.e. arbitrary labels, in a lab. But real groups often involve social interactions leading to social ties between group members. Our experiments compare randomly assigned minimal groups to randomly assigned groups involving real social interactions. While adding social ties leads to qualitatively similar, although stronger, in-group favoritism in cooperation, altruistic norm enforcement patterns are qualitatively different between treatments. Our findings contribute to the micro-foundation of theories of group preferences, and caution against generalizations from “minimal” groups to groups with social context. (JEL C92, D64, D71, Z13)

Many economic decisions involve a substantial amount of uncertainty, and therefore crucially depend on how individuals process probabilistic information. In this paper, we investigate the capability for probability judgment in a representative sample of the German population. Our results show that almost a third of the respondents exhibits systematically biased perceptions of probability. The findings also indicate that the observed biases are related to individual economic outcomes, which suggests potential policy relevance of our findings.

This paper presents an experimentally validated survey module to measure six key economic preferences - risk aversion, discounting, trust, altruism, positive and negative reciprocity - in a reliable, parsimonious and cost-effective way. The survey instruments included in the module were the best predictors of preferences revealed in incentivized choice experiments. We also offer a streamlined version of the module that has been optimized and piloted for applications where time efficiency and simplicity are paramount, such as international telephone surveys.

Social capital is a resource that includes the willingness of members of society to cooperate with each other, even when it is not in their own individual material self-interests to do so, or enforce beneficial social norms, even when this is materially costly for the enforcer. Evidence from economic choice experiments suggests that affect may play an important role in the individual-level decision process that generates these behavioral tendencies. Negative affective responses to uncooperative behavior can lead to a breakdown in social capital, if there is no option to punish. Given a punishment option, however, individuals discipline uncooperative types, even though it is materially costly to do so. This can completely counteract the tendency for social capital to decline in repeated interactions. Positive affect, triggered by punishing uncooperative types, appears to play a role in generating this socially beneficial willingness to sanction.

This paper presents the Global Preference Survey, a globally representative dataset on risk and time preferences, positive and negative reciprocity, altruism, and trust. We collected these preference data as well as a rich set of covariates for 80,000 individuals, drawn as representative samples from 76 countries around the world, representing 90 percent of both the world's population and global income. The global distribution of preferences exhibits substantial variation across countries, which is partly systematic: certain preferences appear in combination, and follow distinct economic, institutional, and geographic patterns. The heterogeneity in preferences across individuals is even more pronounced and varies systematically with age, gender, and cognitive ability. Around the world, our preference measures are predictive of a wide range of individual-level behaviors including savings and schooling decisions, labor market and health choices, prosocial behaviors, and family structure. We also shed light on the cultural origins of preference variation around the globe using data on language structure.

This paper investigates how risk attitudes change over the life course. We study the age trajectory of risk attitudes all the way from early adulthood until old age, in large representative panel data sets from the Netherlands and Germany. Age patterns are generally difficult to identify separately from cohort or calendar period effects. We achieve identification by replacing calendar period indicators with controls for the specific underlying factors that may change risk attitudes across periods. The main result is that willingness to take risks decreases over the life course, linearly until approximately age 65 after which the slope becomes flatter.

Analysis techniques of internal combustion engines range from thermodynamic methods to complex engine design programs. Thermodynamic analyses preclude engine timing while the details of engine design programs are beyond the level of undergraduate courses. This article combines the ideal gas law with heat release models and an engineering equation solver to demonstrate timing in spark and compression ignition internal combustion engines in a manner that can be used in undergraduate courses.

This study presents results of the validation of an ultra-short survey measure of patience included in the German Socio-Economic Panel (SOEP). Survey responses predict intertemporal choice behavior in incentive-compatible decisions in a representative sample of the German adult population. This is the author’s version of a work that was accepted for publication in Economics Letters. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Economics Letters 120(2013), 2, pp. 142-145 and is online available at http://dx.doi.org/10.1016/j.econlet.2013.04.007.

In order to determine the effects of stump height, year of cutting, parent-tree size, logging damage, and deer browsing on bigleaf maple (Acer macrophyllum) sprout clump development, maple trees were cut to two stump heights at three different times. Stump height had the greatest impact on sprout clump size. Two years after clearcutting, the sprout clump volume for short stumps was significantly less than that for tall stumps. The sprout clump volume, area, and number of sprouts were significantly less for trees cut 1 and 2 yr before harvest than for trees cut at harvest. Sprout clump size was positively correlated with parent tree stem diameter and stump volume, and negatively correlated with the percentage of bark removed during logging. Browsing had no significant impact on average clump size. Uncut trees produced sprout clumps at their base and epicormic branches along the length of their stems; thus their crown volume averaged four to five times that of cut trees. Cutting maple in clearcuts to low stumps may reduce maple competition with Douglas-fir regeneration and still maintain maple in the next stand. West. J. Appl. For. 11(4):120-124.

We compare different designs that have been used to test for an impact of time horizon on discounting, using real incentives and two representative data sets. With the most commonly used type of design we replicate the typical finding of declining (hyperbolic) discounting, but with other designs find constant or increasing discounting. As a whole, the data are not consistent with any of these usual candidate discounting assumptions, and they also imply a violation of transitivity. The results have implications for interpreting previous evidence, and pose an important puzzle for understanding inter-temporal choice. JEL-Code: D010, D900, D030, E210.

This study presents results of the validation of an ultra-short survey measure of patience included in the German Socio-Economic Panel (SOEP). Survey responses predict intertemporal choice behavior in incentive-compatible decisions in a representative sample of the German adult population.

Centrocestus formosanus (Trematoda: Heterophyidae) is an invasive fish parasite in the Comal River, Texas, and is considered a threat to the federally endangered fountain darter, Etheostoma fonticola . Monitoring densities of C. formosanus cercariae is crucial to determining levels of infection pressure. We sampled 3 sites in the Comal River during 2 sampling periods, the first during 2006-2007, and again during 2009-2010. Two of the sites were located in the upstream reach of Landa Lake, sites HS and LA, and the third site was located downstream of Landa Lake in the old channel of the river. Cercariae densities were highest at the downstream most site (EA), followed by sites LA and HS, during both sampling periods, but a significant decline in cercariae density was observed between the first and second sampling periods. Several abiotic factors were monitored, including total stream discharge, wading discharge, temperature, and dissolved oxygen, but no river-wide trends were observed. Therefore, we speculate that these factors do not adequately explain the observed long-term decline in cercariae density. We propose that the decline is simply a reflection of a typical pattern followed by most invasive species as they gradually become integrated into the local community following an initial explosive growth in population size. Although cercariae densities may be abating, fountain darters in the Comal River are still threatened by the parasite, and conservation efforts must focus on reducing levels of infection pressure from the parasite whenever possible.

This study discusses a fi eld experiment on default options and savings decisions by low-income households at the time of federal tax fi ling. In the treatment, a fraction of the tax refund was automatically directed to U.S. Savings Bonds unless fi lers actively chose another allocation. We fi nd that this opt-out default had no impact on savings, and our treatment estimate is suffi ciently precise to reject effects as small as 20 percent of those found in the literature on defaults and 401(k) plans. Our results have implications for understanding when default interventions will be effective and when their infl uence will be limited.

Firms are often organized into groups. Group membership has been shown empirically to have positive effects, in the form of increased pro-social behavior towards in-group members. This includes an enhanced willingness to engage in altruistic punishment of inefficient defection. Our paper provides evidence of a dark side of group membership. In the presence of cues of competition between groups, a taste for harming the out-group emerges: punishment ceases to serve a norm enforcement function, and instead, out-group members are punished harder and regardless of whether they cooperate or defect. Our results point to a mechanism that might help explain previous mixed results on the social value of punishment, and also contribute to understanding the sources of conflict between groups. They also point to an important tradeoff for firms: introducing competition enhances within-group efficiency, but also generates costly between-group conflict.

We investigate how group boundaries, and the economic environment surrounding groups, affect altruistic cooperation and punishment behavior. Our study uses experiments conducted with 525 officers in the Swiss Army, and exploits random assignment to platoons. We find that, without competition between groups, individuals are more prone to cooperate altruistically in a prisoner's dilemma game with in-group as opposed to out-group members. They also use a costly punishment option to selectively harm those who defect, encouraging a norm of cooperation towards the group. Adding competition between groups causes even stronger in-group cooperation, but also a qualitative change in punishment: punishment becomes anti-social, harming cooperative and defecting out-group members alike. These findings support recent evolutionary models and have important organizational implications.

The F-35 Joint Strike Fighter (JSF) incorporates the latest technology for aerial warfighting. To support this aircraft's mission and to provide the pilot with the increased situational awareness needed in today's battlespace, a panoramic AMLCD was developed and is being deployed for the first time. This 20" by 8" display is the largest fielded to date in a tactical fighter. Key system innovations had to be employed to allow this technology to function in this demanding environment. Certain older generation aircraft are now considering incorporating a panoramic display to provide their crews with this level of increased capability. Key design issues that had to be overcome dealt with sunlight readability, vibration resistance, touchscreen operation, and reliability concerns to avoid single-point failures. A completely dual redundant system design had to be employed to ensure that the pilot would always have access to critical mission and flight data.

Geographic mobility is important for the functioning of labor markets because it brings labor resources to where they can be most efficiently used. It has long been hypothesized that individuals' migration propensities depend on their attitudes towards risk, but the empirical evidence, to the extent that it exists, has been indirect. In this paper, we use newly available data from the German Socio-Economic Panel to measure directly the relationship between migration propensities and attitudes towards risk. We find that individuals who are more willing to take risks are more likely to migrate between labor markets in Germany. This result is robust to stratifying by age, sex, education, national origin, and a variety of other demographic characteristics, as well as to the level of aggregation used to define geographic mobility. The effect is substantial relative to the unconditional migration propensity and compared to the conventional determinants of migration. We also find that being more willing to take risks is more important for the extensive than for the intensive margin of migration.

This paper complements the experimental literature that has shown theimportance of reciprocity for behaviour in stylized labour markets or otherdecision settings. We use individual measures of reciprocal inclinations in alarge, representative survey, and relate reciprocity to real world labour marketbehaviour and life outcomes. We find that reciprocity matters, and we find thatthe way in which it matters is very much in line with the experimental evidence.In particular, positive reciprocity is associated with receiving higher wages andworking harder. Negatively reciprocal inclinations tend to reduce effort. Firmsdo not pay lower wages to individuals with strong negatively reciprocalinclinations. Instead, negative reciprocity increases the likelihood of beingunemployed. Looking at broader measures of success, in terms of number ofclose friends, and subjective well-being, we find that positively reciprocalinclination are associated with greater happiness and ability to sustain friendshiprelations, with the opposite being true for negative reciprocity.

This flexible display and integrated communication device (FDICD) technology program sought to create a family of powerful visualization technologies that would reduce the weight, volume, and power while increasing usability by integrating many of the functions of present mission equipment into a small form factor. The goals included a network comprised of a worn main computer, a hand-held or knee-worn large display system and a wrist-worn small display. The large display was to be eventually rollable to provide soldiers with a large image of at least super video graphics adapter (SVGA) color resolution when needed, but small form factor when stowed, for viewing of and team collaboration with tactical information such as battlefield maps, GIS imaging data, command/control plots, and global positioning system (GPS)-assisted navigational maps. The wrist system was to provide a readily viewable unit in situations where the larger unit cannot be deployed and without resorting to headgear, which blocks battlespace view-ability. This final phase of the program resulted in two separate wrist demonstration devices. The first device built upon the results of the first phase of the project to raise the technology readiness level (TRL) of the commercial personal digital assistant (PDA)-based unit to a level suitable for the intended military environment, including full water-immersion capability. The second device was a custom designed wrist display intended to demonstrate additional capability on the wrist, including GPS maps.

Recent theories endogenize the attitude endowments of individuals, assuming that they are shaped by the attitudes of parents and other role models. This paper tests empirically for the relevance of three aspects of the attitude transmission process highlighted in this theoretical literature: (1) transmission of attitudes from parents to children; (2) an impact of prevailing attitudes in the local environment on child attitudes; and (3) positive assortative mating of parents, which enhances the ability of a parent to pass on his or her attitudes to the child. We focus on two fundamentally important attitudes, willingness to take risks and willingness to trust others. We find empirical support for all three aspects, providing an empirical underpinning for the literature. An investigation of underlying mechanisms shows that socialization is important in the transmission process. Various parental characteristics and aspects of family structure are found to strengthen the socialization process, with implications for modeling the socialization production function and for policies focused on affecting children's non-cognitive skills. The paper also provides evidence that the transmission of risk and trust attitudes affects a wide variety of child outcomes, implying a potentially large total effect on children's economic situation. Copyright 2012, Oxford University Press.

We provide evidence on how two important types of institutions – dismissal barriers, and bonus pay – affect contract enforcement behavior in a market with incomplete contracts and repeated interactions. Dismissal barriers are shown to have a strong negative impact on worker performance, and market efficiency, by interfering with firms' use of firing threat as an incentive device. Dismissal barriers also distort the dynamics of worker effort levels over time, cause firms to rely more on the spot market for labor, and create a distribution of relationship lengths in the market that is more extreme, with more very short and more very long relationships. The introduction of a bonus pay option dramatically changes the market outcome. Firms are observed to substitute bonus pay for threat of firing as an incentive device, almost entirely offsetting the negative incentive and efficiency effects of dismissal barriers. Nevertheless, contract enforcement behavior remains fundamentally changed, because the option to pay bonuses causes firms to rely less on long-term relationships. Our results show that market outcomes are the result of a complex interplay between contract enforcement policies and the institutions in which they are embedded.

This paper presents new evidence on the distribution of risk attitudes in the population, using a novel set of survey questions and a representative sample of roughly 22,000 individuals living in Germany. Using a question that asks about willingness to take risks on an 11-point scale, we find evidence of heterogeneity across individuals, and show that willingness to take risks is negatively related to age and being female, and positively related to height and parental education. We test the behavioral relevance of this survey measure by conducting a complementary field experiment, based on a representative sample of 450 subjects, and find that the measure is a good predictor of actual risk-taking behavior. We then use a more standard lottery question to measure risk preference, and find similar results regarding heterogeneity and determinants of risk preferences. The lottery question makes it possible to estimate the coefficient of relative risk aversion for each individual in the sample. Using five questions about willingness to take risks in specific domains - car driving, financial matters, sports and leisure, career, and health - the paper also studies the impact of context on risk attitudes, finding a strong but imperfect correlation across contexts. Using data on a collection of risky behaviors from different contexts, including traffic offenses, portfolio choice, smoking, occupational choice, participation in sports, and migration, the paper compares the predictive power of all of the risk measures. Strikingly, the general risk question predicts all behaviors whereas the standard lottery measure does not. The best overall predictor for any specific behavior is typically the corresponding context-specific measure. These findings call into the question the current preoccupation with lottery measures of risk preference, and point to variation in risk perceptions as an understudied determinant of risky behavior.