Forthcoming

October 2014

Nobel Lecture: Uncertainty Outside and Inside Economic Models
Lars Peter Hansen
 
We must infer what the future situation would be without our interference, and what changes will be wrought by our actions. Fortunately, or unfortunately, none of these processes is infallible, or indeed ever accurate and complete. Knight (1921)
 


 
Coagglomeration, Clusters, and the Scale and Composition of Cities
Robert W. Helsley and William C. Strange
 
Cities are neither completely specialized nor completely diverse. However, prior research has focused almost entirely on the polar cases of complete specialization and complete diversity. This paper develops a model that can also generate the intermediate case of cities that feature the coagglomeration of some but not all industries, thus giving theoretical foundations to the analysis of business clusters. The analysis sharply challenges the conventional wisdom that the size and composition of cities are necessarily driven primarily by agglomerative efficiencies.
 


 
Implementing the “Wisdom of the Crowd”
Ilan Kremer, Yishay Mansour, and Motty Perry
 
We study a novel mechanism design model in which agents each arrive sequentially and choose one action from a set of actions with unknown rewards. The information revealed by the principal affects the incentives of the agents to explore and generate new information. We characterize the optimal disclosure policy of a planner whose goal is to maximize social welfare. One interpretation of our result is the implementation of what is known as the “wisdom of the crowd”. This topic has become increasingly relevant with the rapid spread of the Internet over the past decade.
 


 
Mechanism Design with Communication Constraints
Dilip Mookherjee and Masatoshi Tsumagari
 
We consider mechanism design where message sets are restricted owing to communication costs, preventing full revelation of information. A Principal contracts with multiple agents each supplying a one-dimensional good at a privately known cost. We characterize optimal mechanisms subject to incentive and communication constraints, without imposing arbitrary restrictions on the number of communication rounds. We show mechanisms which centralize production decisions are strictly dominated by those which decentralize decision-making authority to agents, and optimal communication mechanisms maximize information exchanged directly among agents. Conditions are provided for these to involve gradual release of information over multiple rounds either simultaneously or sequentially.
 


 
Crime and the Depenalization of Cannabis Possession: Evidence from a Policing Experiment
Jerome Adda, Brendon McConnell, and Imran Rasul
 
We evaluate the impact on crime of a localized policing experiment that depenalized the possession of small quantities of cannabis in the London borough of Lambeth. We find that depenalization policy caused the police to reallocate effort towards non-drug crime. Despite the overall fall in crime attributable to the policy, we find the total welfare of local residents likely fell, as measured by house prices. We shed light on what would be the impacts on crime of a citywide depenalization policy, by developing and calibrating a structural model of the market for cannabis and crime.
 


 
Dynamic Inputs and Resource (Mis)Allocation
John Asker, Allan Collard-Wexler, and Jan De Loecker
 
We investigate the role of dynamic production inputs and their associated adjustment costs in shaping the dispersion of static measures of capital misallocation within industries (and countries). Across 9 datasets, spanning 40 countries, we find that industries exhibiting greater time-series volatility of productivity have greater cross-sectional dispersion of the marginal revenue product of capital. We use a standard investment model with adjustment costs to show that variation in the volatility of productivity across these industries and economies can explain a large share (80-90%) of the cross-industry (and cross-country) variation in the dispersion of the marginal revenue product of capital.
 


 

December 2014

Racial Disparity in Federal Criminal Sentences
M. Marit Rehavi and Sonja B. Starr
 
Using rich data linking federal cases from arrest through to sentencing, we find that initial case and defendant characteristics, including arrest offense and criminal history, can explain most, but not all, of the large raw racial disparity in federal sentences. Across the sentence distribution, blacks receive sentences that are almost 10% longer than comparable whites arrested for the same crimes. Most of this disparity can be explained by prosecutors’ initial charging decisions, particularly the filing of charges carrying mandatory minimum sentences. Ceteris paribus, the odds of black arrestees facing such a charge are 1.75 times higher than those of white arrestees.
 


 
Misconceptions and Game Form Recognition: Challenges to Theories of Revealed Preference and Framing
Timothy Cason and Charles Plott
 
This study explores the tension between the standard economic theory of preference and non-standard theories of preference that are motivated by an underlying theory of framing. A simple experiment fails to measure a known preference. The divergence of the measured preference from the known preference reflects a mistake, arising from some subjects' misconception of the game form. We conclude that choice data should not be granted an unqualified interpretation of preference revelation. Mistakes in choices can masquerade as having been produced by non-standard preferences and may reflect an error at the foundation of the theory of framing.
 


 
Competing for Consumer Inattention
Geoffroy de Clippel, Kfir Eliaz, and Kareen Rozen
 
Consumers purchase multiple types of goods, but may be able to examine only a limited number of markets for the best price. We propose a simple model which captures these features, conveying new insights. A firm's price can deflect or draw attention to its market, and consequently, limited attention introduces a new dimension of cross-market competition. We characterize the equilibrium, and show that having partially attentive consumers improves consumer welfare. With less attention, consumers are more likely to miss the best offers; but enhanced cross-market competition decreases average price paid, as leading firms try to stay under the consumers' radar.
 


 
Personality Traits and the Marriage Market
Arnaud Dupuy and Alfred Galichon
 
Which and how many attributes are relevant for the sorting of agents in a matching market? This paper addresses these questions by constructing indices of mutual attractiveness that aggregate information about agents' attributes. The first k indices for agents on each side of the market provide the best approximation of the matching surplus by a k-dimensional model. The methodology is applied on a unique Dutch households survey containing information about education, height, BMI, health, attitude toward risk, and personality traits of spouses.
 


 
Disease and Development Revisited
David E. Bloom, David Canning, and Günther Fink
 
Acemoglu and Johnson (2007) present evidence that improvements in population health do not promote economic growth. We show that their result depends critically on the assumption that initial health has no causal effect on subsequent economic growth. We argue that such an effect is likely, primarily because childhood health affects adult productivity. In our augmented model, which includes initial health, the instrumental variable proposed by Acemoglu and Johnson has no significant predictive power for improvements in health and does not identify the effect of contemporaneous improvements in health on economic growth.
 


 
Disease and Development: A Reply to Bloom, Canning, and Fink
Daron Acemoglu and Simon Johnson
 
Bloom, Canning, and Fink (2014) argue that the results in Acemoglu and Johnson (2006, 2007) are not robust because initial level of life expectancy (in 1940) should be included in our regressions of changes in GDP per capita on changes in life expectancy. We assess their claims controlling for potential lagged effects of initial life expectancy using data from 1900, employing a nonlinear estimator suggested by their framework, and using information from microeconomic estimates on the effects of improving health. There is no evidence for a positive effect of life expectancy on GDP per capita in this important historical episode.
 


 

February 2015

Leverage and the Foreclosure Crisis
Dean Corbae and Erwan Quintin
 
How much of the foreclosure crisis can be explained by the large number of high-leverage mortgages originated during the housing boom? In our model, heterogeneous households select from mortgages with different down payments and choose whether to default given income and housing shocks. The use of low-down payment loans is initially limited by payment-to-income requirements but becomes unrestricted during the boom. The model approximates key housing and mortgage market facts before and after the crisis. A counterfactual experiment suggests that the increased number of high-leverage loans originated prior to the crisis can explain over 60% of the rise in foreclosure rates.
 


 
Measuring Returns to Hospital Care: Evidence from Ambulance Referral Patterns
Joseph J. Doyle, Jr., John A. Graves, Jonathan Gruber, and Samuel A. Kleiner
 
We consider whether hospitals that receive higher payments from Medicare improve patient outcomes, using exogenous variation in ambulance-company assignment among patients who live near one another. Using Medicare data from 2002-2010 on assignment across ambulance companies and New York State date from 2002-2006 on assignment across area boundaries, we find that patients who are brought to higher cost hospitals achieve better outcomes. Our estimates imply that a one standard deviation increase in Medicare reimbursement leads to a 4 percentage point (or 10 percent) reduction in mortality; the implied cost per at least one year of life saved is approximately $80,000.
 


 
Suspense and Surprise
Jeffrey Ely, Alexander Frankel, and Emir Kamenica
 
We model demand for non-instrumental information, drawing on the idea that people derive entertainment utility from suspense and surprise. A period has more suspense if the variance of the next period's beliefs is greater. A period has more surprise if the current belief is further from the last period's belief. Under these definitions, we analyze the optimal way to reveal information over time so as to maximize expected suspense or surprise experienced by a Bayesian audience. We apply our results to the design of mystery novels, political primaries, casinos, game shows, auctions, and sports.
 


 
Asset Pricing and Asymmetric Reasoning
Elena Asparouhova, Peter Bossaerts, Jon Eguia, and William Zame
 
We present a theory and experimental evidence on pricing and portfolio choices under asymmetric reasoning. We show that under asymmetric reasoning, prices do not reflect all (types of) reasoning. Some agents who observe prices that cannot be reconciled with their reasoning switch from perceiving the environment as risky to perceiving it as ambiguous. If they are ambiguity averse, these agents become price-insensitive. Results from an experiment show that, consistent with the theory, i) without aggregate risk, mispricing decreases as the fraction of price-sensitive agents increases, and ii) with aggregate risk, price-insensitive agents trade to more balanced portfolios.
 


 
The Origins of Savings Behavior
Henrik Cronqvist and Stephan Siegel
 
Analyzing the savings behavior of a large sample of identical and fraternal twins, we find that genetic differences explain about 33 percent of the variation in savings propensities across individuals. Individuals are born with a persistent genetic predisposition to a specific savings behavior. Parenting contributes to the variation in savings rates among younger individuals, but its effect decays over time. The environment when growing up (e.g., parents’ wealth) moderates genetic effects. Finally, savings behavior is genetically correlated with income growth, smoking, and obesity, suggesting that the genetic component of savings behavior reflects genetic variation in time preferences or self-control.
 


 

April 2015

Aligning Learning Incentives of Students and Teachers: Results from a Social Experiment in Mexican High Schools
Jere R. Behrman, Susan W. Parker, Petra E. Todd, and Kenneth I. Wolpin
 
This paper evaluates the impact of three different performance incentives schemes using data from a social experiment that randomized 88 Mexican high schools with over 40,000 students into three treatment groups and a control group. Treatment one provides individual incentives for performance on curriculum-based mathematics tests to students only, treatment two to teachers only and treatment three gives both individual and group incentives to students, teachers and school administrators. Program impact estimates reveal the largest average effects for treatment three, smaller impacts for treatment one and no impact for treatment two.
 


 
Estimating the Cream Skimming Effect of School Choice
Joseph G. Altonji, Ching-I Huang, and Christopher R. Taber
 
We derive a simple formula that may be used to determine the degree to which a school choice program may harm public school stayers by luring the best students to other schools. The formula shows that the “cream-skimming” effect is increasing in the degree of heterogeneity within schools, the school choice take up rate of strong students relative to weak students, and the dependence of school outcomes on student body quality. We use the formula to investigate the cream skimming effect of hypothetical voucher programs on the high school graduation rate and other outcomes of the students who would remain in public school. We employ NELS:88 data to measure the characteristics of public school students, to estimate a model of the private school entrance decision, and to estimate student body effects on graduation. We supplement the econometric estimates with a wide range of alternative assumptions about school choice and student body effects. We find that the cream skimming effect is small and that this result is robust across a wide variety of model specifications and types of modest voucher programs.
 


 
Linear Social Interactions Models
Lawrence E. Blume, William A. Brock, Steven N. Durlauf, and Rajshri Jayaraman
 
This paper provides a systematic analysis of identification in linear social interactions models. This is both a theoretical and an econometric exercise as the analysis is linked to a rigorously delineated model of interdependent decisions. We develop an incomplete information game that describes individual choices in the presence of social interactions. The equilibrium strategy profiles are linear. Standard models in the empirical social interactions literature are shown to be exact or approximate special cases of our general framework, which in turn provides a basis for understanding the microeconomic foundations of those models. We consider identification of both endogenous (peer) and contextual social effects under alternative assumptions regarding the analyst’s a priori knowledge of network structure or access to individual-level or aggregate data. Finally, we discuss potential ramifications for identification of endogenous group selection.
 


 
The Generalized Roy Model and the Cost-Benefit Analysis of Social Programs
Philipp Eisenhauer, James J. Heckman, and Edward Vytlacil
 
The literature on treatment effects focuses on gross benefits from program participation. We extend this literature by developing conditions under which it is possible to identify parameters measuring the cost and net surplus from program participation. Using the generalized Roy model, we nonparametrically identify the cost, benefit, and net surplus of selection into treatment without requiring the analyst to have direct information on the cost. We apply our methodology to estimate the gross benefit and net surplus of attending college.
 


 
A Flying Start? Maternity Leave Benefits and Long Run Outcomes of Children
Pedro Carneiro, Katrine V. Løken, and Kjell G. Salvanes
 
We study the impact of increasing maternity leave benefits on long run outcomes of children, by examining a reform that increased paid and unpaid maternity leave in Norway as of July 1st 1977. Mothers giving birth before this date were eligible only for 12 weeks of unpaid leave, while those giving birth after were entitled to four months of paid leave and 12 months of unpaid leave. This increased time with the child led to a two percentage points decline in high school dropout rates and a five% increase in wages at age 30. These effects are especially large for children of those mothers who, prior to the reform, would take very low levels of unpaid leave.
 


 
How Effective Is the Minimum Wage at Supporting the Poor?
Thomas MaCurdy
 
The efficacy of minimum wage policies as an antipoverty initiative depends on which families benefit from the increased earnings attributable to minimum wages and which families pay for these higher earnings. Proponents of these policies contend that employment impacts experienced by low-wage workers are negligible and, therefore, these workers do not pay. Instead proponents typically suggest that consumers pay for the higher labor costs through imperceptible increases in the prices of goods and services produced by low-wage labor. Adopting this “best-case” scenario from minimum-wage advocates, this study projects the consequences of the increase in the national minimum wage instituted in 1996 on the redistribution of resources among rich and poor families. Under this scenario, the minimum wage increase acts like a value-added or sales tax in its effect on consumer prices, a tax that is even more regressive than a typical state sales tax. With the proceeds of this national value-added tax collected to fund benefits, the 1996 increase in the minimum wage distributed the bulk of these benefits to one in four families nearly evenly across the income distribution. Far more poor families suffered reductions in resources than those who gained. As many rich families gained as poor families. These income transfer properties of the minimum wage document its considerable inefficiency as an antipoverty policy.
 


 

Awaiting Scheduling

Robust Comparative Statics in Large Dynamic Economies
Daron Acemoglu and Markin Kaae Jensen
 
We consider infinite horizon economies populated by a continuum of agents subject to idiosyncratic shocks. This framework contains models of saving and capital accumulation with incomplete markets in the spirit of works by Bewley, Aiyagari, and Huggett, and models of entry, exit and industry dynamics in the spirit of Hopenhayn's work as special cases. Robust and easy-to-apply comparative statics results are established with respect to exogenous parameters as well as various kinds of changes in the Markov processes. These results complement existing literature's numerical methods applied to this class of models and are illustrated using a number of examples.
 


 
Young, Old, Conservative, and Bold: The Implications of Heterogeneity and Finite Lives for Asset Pricing
Nicolae Garleanu and Stavros Panageas
 
We study the implications of preference heterogeneity for asset pricing. We use recursive preferences in order to separate risk-aversion heterogeneity from IES heterogeneity, and an overlapping-generations framework to obtain a non-degenerate stationary equilibrium. We solve the model explicitly up to the solutions of ordinary differential equations, and highlight the effects of overlapping generations and each dimension of preference heterogeneity on the market price of risk, interest rates, and the volatility of stock returns. We find that separating IES and risk-aversion heterogeneity can have a substantive impact on the model's (qualitative and quantitative) ability to address some key asset pricing issues.
 


 
Comment on the Campbell-Cochrane Habit Model
Lars Ljungqvist and Harald Uhlig
 
Campbell and Cochrane (1999) formulate a model that successfully explains a wide variety of asset pricing puzzles, by augmenting the standard power utility function with a time-varying “external habit,” that adapts nonlinearly to current and past average consumption in the economy. We demonstrate that their preference specification has the unusual implications that habit can move negatively with consumption, and that reductions in consumption can increase welfare. As a result, government interventions that occasionally destroy part of the aggregate endowment can lead to substantial welfare improvements.
 


 
Participation and Duration of Environmental Agreements
Bard Harstad and Marco Battaglini
 
We analyze participation in international environmental agreements (IEAs) in a dynamic game where countries pollute and invest in green technologies. If complete contracts are feasible, participants eliminate the hold-up problem associated with their investments; however, most countries prefer to free-ride rather than participate. If investments are non-contractible, countries face a hold-up problem every time they negotiate; but the free-rider problem can be mitigated and significant participation is feasible. Participation becomes attractive because only large coalitions commit to long-term agreements that circumvent the hold-up problem. Under well-specified conditions even the first-best outcome is possible when the contract is incomplete. Since real-world IEAs fit in the incomplete contracting environment, our theory may help explaining the rising importance of IEAs and how they should be designed.
 


 
Evolving Comparative Advantage and the Impact of Climate Change in Agricultural Markets:
Evidence from 1.7 Million Fields around the World
Arnaud Costinot, Dave Donaldson, and Cory Smith
 
A large agronomic literature models the implications of climate change for a variety of crops and locations around the world. The goal of the present paper is to quantify the macro-level consequences of these micro-level shocks. Using an extremely rich micro-level dataset that contains information about the productivity—both before and after climate change—of each of 10 crops for each of 1.7 million fields covering the surface of the Earth, we find that the impact of climate change on these agricultural markets would amount to a 0.26% reduction in global GDP when trade and production patterns are allowed to adjust.
 


 
Market-Based Emissions Regulation and Industry Dynamics
Meredith Fowlie, Mar Reguant, and Stephen Ryan
 
We assess the static and dynamic implications of alternative market-based policies limiting greenhouse gas emissions in the US cement industry. Our results highlight two countervailing market distortions. First, emissions regulation exacerbates distortions associated with the exercise of market power in the domestic cement market. Second, emissions \leakage” in trade exposed markets offsets domestic emissions reductions. Taken together, these forces can result in social welfare losses under policy regimes that fully internalize the emissions externality. Market-based policies that incorporate design features to mitigate the exercise of market power and emissions leakage deliver welfare gains when damages from carbon emissions are high.
 


 
Political Economy in a Changing World
Daron Acemoglu, Georgy Egorov, and Konstantin Sonin
 
We provide a general framework for the analysis of the dynamics of institutional change (e.g., democratization, extension of political rights, or repression of different groups), and how these dynamics interact with (anticipated and unanticipated) changes in the distribution of political power and in economic structure. We focus on Markov Voting Equilibria, which require that economic and political changes should take place if there exists a subset of players with the power to implement such changes and who will obtain higher expected discounted utility by doing so. Assuming that economic and political institutions as well as individual types can be ordered, and preferences and the distribution of political power satisfy natural “single crossing” (increasing differences) conditions, we prove the existence of a pure-strategy equilibrium, provide conditions for its uniqueness, and present a number of comparative static results that apply at this level of generality. We then use this framework to study the dynamics of political rights and repression in the presence of radical groups that can stochastically grab power and the dynamics of collective experimentation over institutions.
 


 
Environmental Regulations and Corruption: Automobile Emissions in Mexico City
Paulina Oliva
 
Emission regulations become more prevalent in developing countries; but they may be compromised by corruption. This paper documents the prevalence of corruption and the effectiveness of vehicle emission regulations in Mexico City. I develop a statistical test for identifying a specific type of cheating that involves bribing center technicians. I also estimate a structural model of car owner retesting and cheating decisions. Results suggest that 9.6 percent of car owners paid 20 U.S. dollars to circumvent the regulation. Eliminating cheating and increasing the cost of retests would reduce emissions by 3,708 tons at a high cost for vehicle owners.
 


 
Uncertainty and Disagreement in Equilibrium Models
Nabil I. Al-Najjar and Eran Shmaya
 
Leading equilibrium concepts require agents' beliefs to coincide with the model's true probabilities and thus be free of systematic errors. This implicitly assumes a criterion that tests beliefs against the observed outcomes generated by the model. We formalize this requirement in stationary environments. We show that there is a tension between requiring that beliefs can be tested against systematic errors, on the one hand, and allowing agents to disagree or be uncertain about the long-run fundamentals. We discuss the application of our analysis to asset pricing, Markov perfect equilibria, and dynamic games.
 


 
Women and Power: Unpopular, Unwilling, or Held Back?
Pablo Casas-Arce and Albert Saiz
 
We use Spain’s Equality Law, which mandates a 40 percent female quota on electoral lists, to test for the existence of agency problems between party leaders and their constituents regarding women’s political representation. The law was enacted by the Social-Democratic Party after the surprise parliamentary electoral results following the Madrid terrorist bombings in 2004. It was therefore completely unexpected by local political organizations. The quota only applied to towns with populations above 5,000 and forced heterogeneous growth in the number of female candidates by party. Using pre- and post-quota data by party and municipality, we implement a triple-difference design and find that female quotas resulted in slightly better electoral results for the parties that started out with fewer women, and hence were most affected by the quota. Our evidence suggests the existence of agency problems that hinder female representation in political institutions, because party leaders were not maximizing electoral results prior to the introduction of the quota.
 


 
Economic Effects of Runs on Early “Shadow Banks”: Trust Companies and the Impact of the Panic of 1907
Carola Frydman, Eric Hilt, and Lily Y. Zhou
 
We use the unique circumstances that led to the Panic of 1907 to analyze its impact on economic activity. The panic was fuelled by runs on the ‘shadow banks’ of the time, New York’s trust companies. But the shock that triggered the runs was unrelated to the nonfinancial corporations affiliated with those institutions. Using newly collected data, we find that small corporations with close ties to the trust companies that lost the most deposits experienced an immediate decline in their stock price of 10.4 percentage points, and performed worse in the years following the panic across a range of outcomes, including their return on equity, which fell 13.1 percent, their dividend rate, which fell 22 percent, and their average interest costs, which rose 8.3 percent, relative to mean prepanic levels. The effect on their investment rate was much greater: it fell by nearly 50 percent. The relative decline in investment induced by affiliations with the worst-affected trust companies alone accounted for at least 18.4 percent of the total decline in corporate investment in the United States in 1908. This effect diminished in magnitude over time but persisted for at least five years following the panic.
 


 
Bonus Culture: Competitive Pay, Screening, and Multitasking
Roland Bénabou and Jean Tirole
 
To analyze the impact of labor market competition on the structure of compensation, we embed multitasking and screening within a Hotelling framework. Competition for talent leads to an escalation of performance pay, shifting effort away from long-term investments, risk management, and cooperation. Efficiency losses can exceed those from a single principal, who dulls incentives to extract rents. As competition intensifies, monopsonistic underincentivization of low-skill agents first decreases, then gives way to growing overincentivization of high-skill ones. Aggregate welfare is thus hill-shaped, while inequality tends to rise monotonically. Bonus caps can help restore balance in incentives, but may generate other distortions.
 


 
Poultry in Motion: A Study of International Trade Finance Practices
Pol Antràs and C. Fritz Foley
 
This paper analyzes the financing terms that support international trade and sheds light on how these terms shape the impact of economic shocks on trade. Analysis of transaction-level data from a U.S.-based exporter of frozen and refrigerated food products, primarily poultry, reveals broad patterns about the use of alternative financing terms. These patterns help discipline a model in which the choice of trade finance terms is shaped by the risk that an importer defaults on an exporter and by the possibility that an exporter does not deliver goods as specified in the contract. The empirical results indicate that cash in advance and open account terms are much more commonly used than letter of credit and documentary collection terms. Transactions are more likely to occur on cash in advance or letter of credit terms when the importer is located in a country with weak contractual enforcement. As an importer develops a relationship with the exporter, transactions are less likely to occur on terms that require prepayment. During the recent crisis, the exporter was more likely to demand cash in advance terms when transacting with new customers, and customers that traded on cash in advance and letter of credit terms prior to the crisis decreased their purchases by 17.3% more than other customers. The model illustrates that these findings can be rationalized if (i) misbehavior on the part of the exporter is of little concern to importers, and (ii) local banks in importing countries are more effective than the exporter in pursuing financial claims against importers.
 


 
Self-Control at Work
Supreet Kaur, Michael Kremer, and Sendhil Mullainathan
 
Workers with self-control problems do not work as hard as they would like. This changes the logic of agency theory by partly aligning the interests of the firm and worker: both now value contracts that elicit more effort in the future. Three findings from a year-long field experiment with data entry workers suggest the quantitative importance of self control at work. First, workers choose dominated contracts—which penalize low output but provide no greater reward for high output—36% of the time to motivate their future selves; use of these contracts increases output by the same amount as an 18% increase in the piece-rate. Second, effort increases as the (randomly assigned) payday gets closer: output rises 8% over the pay week; calibrations show that justifying this would require a 4% daily exponential discount rate. Third, for both findings there is significant and correlated heterogeneity: workers with larger payday effects are both more likely to choose dominated contracts and show greater output increases under them. This correlation grows with experience, consistent with the hypothesis that workers learn about their self-control problems over time. Self-control problems among workers could potentially lead firms to either adopt high-powered incentives or impose work rules to allow monitoring of worker effort.
 


 
The Anatomy of French Production Hierarchies
Lorenzo Caliendo, Ferdinando Monte, and Esteban Rossi-Hansberg
 
We use a comprehensive dataset of French manufacturing firms to study their internal organization. We first divide the employees of each firm into layers using occupational categories. Layers are hierarchical in that the typical worker in a higher layer earns more, and the typical firm occupies less of them. In addition, the probability of adding/dropping a layer is very positively/negatively correlated with value added. We then explore the changes in the wages and number of employees that accompany expansions in layers, or output. The empirical results indicate that reorganization, through changes in layers, is key to understanding how firms expand and contract. For example, we find that firms that expand substantially add layers and pay lower average wages, in part by hiring less experienced employees, in all pre-existing layers. In contrast, firms that expand little and do not reorganize pay higher average wages in all preexisting layers, partly by hiring more educated employees.
 


 
Adverse Selection in the Annuity Market and the Role for Social Security
Roozbeh Hosseini
 
I study the role of social security in providing insurance when there is adverse selection in the annuity market. I calculate welfare gains from mandatory annuitization from the current U.S. social security system using a life-cycle model in which individuals have private information about their mortality. I calibrate the model to the current U.S. social security replacement ratio, the average fraction of retirement wealth that is annuitized and mortality heterogeneity in the Health and Retirement Study. The main findings of the paper are the following: 1) the overall welfare gain from having mandatory annuitization through the current U.S. social security system relative to a laissez-faire benchmark is 0.07 percent of consumption; 2) social security has a large effect on annuity prices because it crowds out demand for annuities by persons who have low survival expectations. This price effect has a negative welfare impact of 0.35 percent of consumption.
 


 
Strategic Mass Killings
Joan Esteban, Massimo Morelli, and Dominic Rohner
 
We provide a model of con.ict and mass killing decisions, to identify the key variables and situations that make mass killings more likely to occur. We predict that mass killings are most likely in countries with large amounts of natural resource rents, polarization, institutional constraints regarding rent sharing, and low productivity of labor. The role of resources like oil, gas, and diamonds and other key determinants of mass killings is confirmed by our empirical results based on country level as well as ethnic group level analysis.
 


 
Entrepreneurs, Risk Aversion and Dynamic Firms
Neus Herranz, Stefan Krasa, and Anne P. Villamil
 
This paper conducts a theoretical and quantitative analysis of how entrepreneurs choose firm size, capital structure, default, and owner consumption to manage firm risk, including how these choices change with risk aversion. We decompose an entrepreneur’s default decision into three elements: the fraction of firm debt; the potential reduction in personal consumption from losing the firm; and the ratio of personal wealth to firm scale, which determines an entrepreneur’s ability to inject personal funds to continue operation. Data from the Survey of Small Business Finances is used to calibrate the model and estimate entrepreneur risk aversion. We determine the evolution of entrepreneur net worth, consumption, and firm assets over time. We find that many entrepreneurs have lower net worth and consumption than non-entrepreneurs with the same preferences, but the densities of the distributions of consumption and net-worth have wide upper tails. Thus, entrepreneurship can be a path toward great wealth and high consumption for the top quantiles of entrepreneurs.
 


 
The Double Power Law in Consumption and Implications for Testing Euler Equations
Alexis Akira Toda and Kieran Walsh
 
We provide evidence suggesting that the cross-sectional distributions of U.S. consumption and its growth rate obey the power law in both the upper and lower tails, with exponents approximately equal to 4. Consequently, high order moments are unlikely to exist, and the generalized method of moments estimation of Euler equations that employs cross-sectional moments may be inconsistent. Through bootstrap studies, we find that the power law appears to generate spurious non-rejection of heterogeneous-agent asset pricing models in explaining the equity premium. Dividing households into age groups, we propose an estimation approach which appears less susceptible to fat tail issues.
 


 
Production vs. Revenue Efficiency with Limited Tax Capacity: Theory and Evidence from Pakistan
Michael Carlos Best, Anne Brockmeyer, Henrik Jacobsen Kleven, Johannes Spinnewijn, and Mazhar Waseem
 
To fight evasion, many developing countries resort to production-inefficient tax policies.
This includes minimum tax schemes whereby firms are taxed on either profits or turnover, depending on which tax liability is larger. Such schemes create non-standard kink points, which allow for eliciting evasion responses to switches between profit and turnover taxes using a bunching approach. Using administrative tax records on corporations in Pakistan, we estimate that turnover taxes reduce evasion by up to 60-70% of corporate income. Incorporating this in a calibrated optimal tax model, we find that switching from profit to turnover taxation increases revenue by 74% without reducing aggregate profits, despite the production inefficiency that it introduces.
 


 
Explaining Cross-Country Productivity Differences in Retail Trade
David Lagakos
 
Many macroeconomists argue that productivity is low in developing countries because of frictions that impede the adoption of modern technologies. I argue that in the retail trade sector, which employs just under twenty percent of the workforce on average, developing countries rationally choose technologies with low measured labor productivity. My theory is that the adoption of modern retail technologies is optimal only when household ownership of complementary durable goods, such as cars, is widespread. Because income is low in the developing world, households own few such durables; hence, retail trade is dominated by traditional technologies with low measured productivity. I show that an implication of this theory is that policies that lead to large increases in measured retail productivity do not necessarily lead to large increases in welfare.
 


 
Carbon Taxes, Path Dependency and Directed Technical Change: Evidence from the Auto Industry
Philippe Aghion, Antoine Dechezleprêtre, David Hemous, Ralf Martin, and John Van Reenen
 
Can directed technical change be used to combat climate change? We construct new firm-level panel data on auto industry innovation distinguishing between “dirty” (internal combustion engine) and “clean” (e.g. electric and hybrid) patents across 80 countries over several decades. We show that firms tend to innovate relatively more in clean technologies when they face higher tax-inclusive fuel prices. Furthermore, there is path dependence in the type of innovation both from aggregate spillovers and from the firm's own innovation history. Using our model we simulate the increases in carbon taxes needed to allow clean technologies to overtake dirty technologies.