Paper # Author Title
Previous research has shown that the reasons for lapsation have important implications regarding the effects of the emerging life settlement market on consumer welfare. We present and empirically implement a dynamic discrete choice model of life insurance decisions to assess the importance of various factors in explaining life insurance lapsations. In order to explain some key features in the data, our model incorporates serially correlated unobservable state variables which we deal with using posterior distributions of the unobservables simulated from Sequential Monte Carlo (SMC) method. We estimate the model using the life insurance holding information from the Health and Retirement Study (HRS) data. Counterfactual simulations using the estimates of our model suggest that a large fraction of life insurance lapsations are driven by i.i.d choice specific shocks, particularly when policyholders are relatively young. But as the remaining policyholders get older, the role of such i.i.d. shocks gets smaller, and more of their lapsations are driven either by income, health or bequest motive shocks. Income and health shocks are relatively more important than bequest motive shocks in explaining lapsations when policyholders are young, but as they age, the bequest motive shocks play a more important role. We also suggest the implications of these findings regarding the effects of the emerging life settlement market on consumer welfare. Download Paper
This paper proposes and studies a tractable subset of Nash equilibria, belief-free review-strategy equilibria, in repeated games with private monitoring. The payoff set of this class of equilibria is characterized in the limit as the discount factor converges to one for games where players observe statistically independent signals. As an application, we develop a simple sufficient condition for the existence of asymptotically efficient equilibria, and establish a folk theorem for N-player prisoner’s dilemma. All these results are robust to a perturbation of the signal distribution, and hence remain true even under almost-independent monitoring. Download Paper
From 1980-2009 the Polish economy experienced structural dislocation. The growth and success of the Solidarity movement represented the shift in manufacturing from Soviet bloc trade to membership in the European Union. This paper examines four independent metrics that measure the changing “sophistication” of trade patterns during this modal shift. The common theme underlying the analysis of these indices is that the Polish economy is resilient and adaptable. Poland is expected to compete effectively in its new economic environment after a period of adjustment and progress. Download Paper
We study stochastic games with an infinite horizon and sequential moves played by an arbitrary number of players. We assume that social memory is finite---every player, except possibly one, is finitely lived and cannot observe events that are sufficiently far back in the past. This class of games includes games between a long-run player and a sequence of short-run players and games with overlapping generations of players. Indeed, any stochastic game with infinitely lived players can be reinterpreted as one with finitely lived players: Each finitely-lived player is replaced by a successor, and receives the value of the successor's payoff. This value may arise from altruism, but the player also receives such a value if he can “sell” his position in a competitive market. In both cases, his objective will be to maximize infinite horizon payoffs, though his information on past events will be limited. An equilibrium is purifiable if close-by behavior is consistent with equilibrium when agents' payoffs in each period are perturbed additively and independently. We show that only Markov equilibria are purifiable when social memory is finite. Thus if a game has at most one long-run player, all purifiable equilibria are Markov. Download Paper
We develop a life-cycle model of the labor market in which different worker-firm matches have different quality and the assignment of the right workers to the right firms is time consuming because of search and learning frictions. The rate at which workers move between unemployment, employment and across different firms is endogenous because search is directed and, hence, workers can choose whether to seek low-wage jobs that are easy to find or high-wage jobs that are hard to find. We calibrate our theory using data on labor market transitions aggregated across workers of different ages. We validate our theory by showing that it correctly predicts the pattern of labor market transitions for workers of different ages. Finally, we use our theory to decompose the age profiles of transition rates, wages and productivity into the effects of age variation in work-life expectancy, human capital and match quality. Download Paper
People often wonder why economists analyze models whose assumptions are known to be false, while economists feel that they learn a great deal from such exercises. We suggest that part of the knowledge generated by academic economists is case-based rather than rule-based. That is, instead of offering general rules or theories that should be contrasted with data, economists often analyze models that are “theoretical cases”, which help understand economic problems by drawing analogies between the model and the problem. According to this view, economic models, empirical data, experimental results and other sources of knowledge are all on equal footing, that is, they all provide cases to which a given problem can be compared. We offer some complexity arguments that explain why case-based reasoning may sometimes be the method of choice; why economists prefer simple examples; and why a paradigm may be useful even if it does not produce theories. Download Paper
We study a decision maker who faces a dynamic decision problem in which the process of information arrival is subjective. By studying preferences over menus of acts, we derive a sequence of utility representations that captures the decision maker’s uncertainty about the beliefs he will hold when choosing from a menu. In the most general model of second-order beliefs, we characterize a notion of "more preference for flexibility" via a subjective analogue of Blackwell’s (1951, 1953) comparisons of experiments. We proceed to analyze a model in which signals are subsets of the state space. The corresponding representation enables us to compare the behavior of two decision makers who expect to learn differently, even if they do not agree on their prior beliefs. The class of information systems that can support such a representation generalizes the notion of modeling information as a partition of the state space. We apply the model to study a decision maker who anticipates subjective uncertainty to be resolved gradually over time. We derive a representation that uniquely identifies both the filtration, which is the timing of information arrival with the sequence of partitions it induces, and the decision maker’s prior beliefs. Download Paper
Using data on MZ (monozygotic, identical) female twins from the Minnesota Twin Registry, we estimate the causal effect of schooling on completed fertility, probability of being childless and age at first birth, using the within-MZ twins methodology. We find strong cross-sectional associations between schooling and the fertility outcomes and some evidence that more schooling causes women to have fewer children and delay childbearing, though not to the extent that interpreting cross-sectional associations as causal would imply. Our conclusions are robust when taking account of (1) endogenous within-twin pair schooling differences due to reverse causality and (2) measurement error in schooling. We also investigate possible mechanisms and find that the effect of women’s schooling on completed fertility is not mediated through husband’s schooling but rather through age at first marriage. Download Paper
This paper studies the aggregate consequences of individual learning in the labor market. Specifically, I examine this issue in a model of directed search on the job. Once matched, a firm-worker pair gradually learns the match-specific quality, taking the history of realized production as signals. Heterogeneity in beliefs about the match quality and in the job search behavior of workers naturally occurs, resulting from a variety of individual histories. I describe the efficient learning and searching strategy and implement the efficient allocations through a market mechanism in which the labor contract depends deterministically on tenure. Consistent with the stylized facts, the model successfully predicts the tenure effect on both the job separation rate and the probability of on-the-job search, and when search frictions are small, the model generates a dispersed wage distribution with a at tail, along the lines of observations. Download Paper
How does the central bank's incentive to build a reputation affect speculators' ability to coordinate and the likelihood of the devaluation outcome during speculative currency crises? What role does market information play in speculators' coordination and the central bank's reputation building? I address these questions in a dynamic regime change game that highlights the interaction between the central bank's reputation building and speculators' individual learning. On the one hand, the central bank has private information about its value from the currency peg and decides whether to maintain it. By defending against speculative attacks, it can build a reputation of defending, which may deter future attacks. On the other hand, speculators individually learn the central bank's value, and such learning may encourage speculators to coordinate an attack. I show that though learning makes the central bank's value approximate common knowledge over time, there is a unique equilibrium when learning is slow. In this equilibrium, no speculator attacks and the central bank sustains the currency peg forever, because the central bank obtains commitment power through the incentive to build a reputation. When learning is fast, there may be equilibria with attacks. In any equilibrium with attacks, the onset of the attack depends on the entire learning process. Once speculators attack, they attack frequently and infinitely often. Consequently, the central bank has no incentive to build a reputation Download Paper
Technological progress is typically a result of trial-and-error research by competing firms. While some research paths lead to the innovation sought, others result in dead ends. Because firms benefit from their competitors working in the wrong direction, they do not reveal their dead-end findings. Time and resources are wasted on projects that other firms have already found to be dead ends. Consequently, technological progress is slowed down, and the society benefits from innovations with delay, if ever. To study this prevalent problem, we build a tractable two-arm bandit model with two competing firms. The risky arm could potentially lead to a dead end and the safe arm introduces further competition to make firms keep their dead-end findings private. We characterize the equilibrium in this decentralized environment and show that the equilibrium necessarily entails significant efficiency losses due to wasteful dead-end replication and a flight to safety - an early abandonment of the risky project. Finally, we design a dynamic mechanism where firms are incentivized to disclose their actions and share their private information in a timely manner. This mechanism restores efficiency and suggests a direction for welfare improvement. Download Paper
Current practice largely follows restrictive approaches to market risk measurement, such as historical simulation or RiskMetrics. In contrast, we propose flexible methods that exploit recent developments in fi nancial econometrics and are likely to produce more accurate risk assessments, treating both portfolio-level and asset-level analysis. Asset-level analysis is particularly challenging because the demands of real-world risk management in financial institutions—in particular, real-time risk tracking in very high-dimensional situations—impose strict limits on model complexity. Hence we stress powerful yet parsimonious models that are easily estimated. In addition, we emphasize the need for deeper understanding of the links between market risk and macroeconomic fundamentals, focusing primarily on links among equity return volatilities, real growth, and real growth volatilities. Throughout, we strive not only to deepen our scienti c understanding of market risk, but also cross-fertilize the academic and practitioner communities, promoting improved market risk measurement technologies that draw on the best of both. Download Paper
Savage (1954) provided a set of axioms on preferences over acts that were equivalent to the existence of an expected utility representation. We show that in addition to this representation, there is a continuum of other “expected utility”representations in which for any act, the probability distribution over states depends on the corresponding outcomes. We suggest that optimism and pessimism can be captured by the stake-dependent probabilities in these alternative representations; e.g., for a pessimist, the probability of every outcome except the worst is distorted down from the Savage probability. Extending the DM’s preferences to be de…ned on both subjective acts and objective lotteries, we show how one may distinguish optimists from pessimists and separate attitude towards uncertainty from curvature of the utility function over monetary prizes. Download Paper
Stochastic sequential bargaining models (Merlo and Wilson (1995, 1998)) have found wide applications in different fields including political economy and macroeconomics due to their flexibility in explaining delays in reaching an agreement. This paper presents new results in nonparametric identification and estimation of such models under different data scenarios. Download Paper
This paper evaluates the macroeconomic and distributional effects of government bailout guarantees for Government Sponsored Enterprises (such as Fannie Mae and Freddy Mac) in the mortgage market. In order to do so we construct a model with heterogeneous, in finitely lived households and competitive housing and mortgage markets. Households have the option to default on their mortgages, with the consequence of having their homes foreclosed. We model the bailout guarantee as a government provided and tax- financed mortgage interest rate subsidy. We fi nd that eliminating this subsidy leads to substantially lower equilibrium mortgage origination and increases aggregate welfare, but has little eff ect on foreclosure rates and housing investment. The interest rate subsidy is a regressive policy: eliminating it benefi ts low-income and low-asset households who did not own homes or had small mortgages, while lowering the welfare of high-income, high-asset households. Download Paper
This paper examines how beliefs about own HIV status aect decisions to engage in risky sexual behavior, as measured by having extramarital sex and/or multiple sex partners. The empirical analysis is based on a panel survey of males from the 2006 and 2008 rounds of the Malawi Diusion and Ideational Change Project (MDICP). The paper first develops a behavioral model of the belief-risky behavior relationship. It then estimates the causal effect of beliefs on risky behavior in a way that takes into account the belief updating mechanisms implied by the model. In particular, the Arellano and Carrasco (2003) semiparametric panel data estimator that is used accommodates both unobserved heterogeneity and belief endogeneity, arising from dependence of current beliefs on past risky behavior. Results show that downward revisions in the belief assigned to being HIV positive increase risky behavior and upward revisions decrease it. We estimate for example that a change in the perceived probability of being HIV positive from 0 to 100% reduces risky behavior between 13.7 and 36.4 percentage points depending on the risky behavior definition and year. Implementation of a modied estimator that allows for misreporting of risky behavior finds the estimates to be downward biased but relatively robust to a wide range of plausible misreporting levels. Download Paper
Conditional cash transfer (CCT) programs link public transfers to human capital investment in hopes of alleviating current poverty and reducing its intergenerational transmission. Whereas nearly all studies of their impacts have focused on youth, these CCT programs may also have an impact on aging adults, by increasing household resources or inducing changes in allocations of time of various household members, that may be of substantial interest, particularly given the rapid aging of most populations. This paper contributes to this under-researched area by examining health and work impacts on the aging for the bestknown and most influential of these programs, the Mexican PROGRESA/Oportunidades program. For a number of health indicators, the program appears to significantly improve health, with impacts that are larger with a greater time receiving the program. However, most of these health impacts are concentrated on women. Download Paper
We propose several connectedness measures built from pieces of variance decompositions, and we argue that they provide natural and insightful measures of connectedness among fi nancial asset returns and volatilities. We also show that variance decompositions defi ne weighted, directed networks, so that our connectedness measures are intimately-related to key measures of connectedness used in the network literature. Building on these insights, we track both average and daily time-varying connectedness of major U.S. financial institutions' stock return volatilities in recent years, including during the financial crisis of 2007-2008. Download Paper
How does the persistence of earnings change over the life cycle? Do workers at different ages face the same variance of idiosyncratic shocks? This paper proposes a novel specification for residual earnings that allows for an age profile in the persistence and variance of labor income shocks. We show that the statistical model is identi fied and estimate it using PSID data. We fi nd that shocks to earnings are only moderately persistent (around 0:75) for young workers. Persistence rises with age up to unity until midway in life. The variance of persistent shocks exhibits a U-shaped profile over the life cycle (with a minimum of 0:01 and a maximum of 0:05). These results suggest that the standard specification in the literature (with constant persistence and variances) cannot capture the earnings dynamics of young workers. We also argue that a calibrated job turnover model can account for these non-flat profiles. The key idea is that workers sort into better jobs and settle down as they age; in turn, magnitudes of wage growth rates decline, thereby decreasing variance of shocks. Furthermore the decline in job mobility results in higher persistence. Finally, we investigate the implications of age pro les for consumption-savings behavior. The welfare cost of idiosyncratic risk implied by the age-dependent income process is 34 percent lower compared with its age-invariant counterpart. This difference is mostly due to a higher degree of consumption insurance for young workers, for whom persistence is moderate. These results suggest that age pro les of persistence and variances should be taken into account when calibrating life-cycle models. Download Paper
We consider repeated games with private monitoring that are "close" to repeated games with public/perfect monitoring. A private monitoring information structure is close to a public monitoring information structure when private signals can generate approximately the same distribution of the public signal once they are aggregated into a public signal by some public coordination device. A player's informational size associated with the public coordination device is the key to inducing truth-telling in nearby private monitoring games when communication is possible. A player is informationally small given a public coordination device if she believes that her signal is likely to have a small impact on the public signal generated by the public coordinating device. We show that a uniformly strict equilibrium with public monitoring is robust in a certain sense: it remains an equilibrium in nearby private monitoring repeated games when the associated public coordination device, which makes private monitoring close to public monitoring, keeps every player informationally small at the same time. We also prove a new folk theorem for repeated games with private monitoring and communication by exploiting the connection between public monitoring games and private monitoring games via public coordination devices. Download Paper
Two often-divergent U.S. GDP estimates are available, a widely-used expenditure side version, GDPE, and a much less widely-used income-side version, GDPI . We propose and explore a "forecast combination" approach to combining them. We then put the theory to work, producing a superior combined estimate of GDP growth for the U.S., GDPC. We compare GDPC to GDPE and GDPI, with particular attention to behavior over the business cycle. We discuss several variations and extensions. Download Paper
We reconsider the economics of protection with an industry subject to increasing returns. Under strong comparative disadvantage in one country, any tariff-distorted equilibrium in which both countries produce the commodity must be unstable. In general, under strong comparative disadvantage, the case for free trade is greater than without increasing returns. Also, exceptionally high tariffs are required to protect a high cost increasing-returns industry. Beneficial tariffs or subsidies for the country with comparative disadvantage become prominent when the country with a comparative advantage faces a relevant capacity constraint. Download Paper
This paper offers a selective, interpretative survey of the literature on the political-support component of the political economy of international trade policy. Much of the literature is characterized either by a discrepancy between what policymakers say they are doing and how the theory models their actions (the Cognitive Dissonance problem) or by a lack of a detailed microeconomic and micro-political foundation (the Black Box problem). Download Paper
We develop a dynamic model of opinion formation in social networks when the information required for learning a payoff-relevant parameter may not be at the disposal of any single agent. Individuals engage in communication with their neighbors in order to learn from their experiences. However, instead of incorporating the views of their neighbors in a fully Bayesian manner, agents use a simple updating rule which linearly combines their personal experience and the views of their neighbors (even though the neighbors’ views may be quite inaccurate). This non-Bayesian learning rule is motivated by the formidable complexity required to fully implement Bayesian updating in networks. We show that, as long as individuals take their personal signals into account in a Bayesian way, repeated interactions lead them to successfully aggregate information and learn the true underlying state of the world. This result holds in spite of the apparent na¨ıvet´e of agents’ updating rule, the agents’ need for information from sources the existence of which they may not be aware of, the possibility that the most persuasive agents in the network are precisely those least informed and with worst prior views, and the assumption that no agent can tell whether her own views or those of her neighbors are more accurate. Download Paper
Conditional cash transfer (CCT) programs have spread worldwide as a new form of social assistance for the poor. Previous evaluations of CCT programs focus mainly on rural settings, and little is known about their effects in urban areas. This paper studies the short-term (one and two-year) effects of the Mexican Oportunidades CCT program on urban children/youth. The program provides financial incentives for children/youth to attend school and for family members to visit health clinics. To participate, families had to sign up for the program and be deemed eligible. Difference-in-difference propensity score matching estimates indicate that the program is successful in increasing school enrollment, schooling attainment and time devoted to homework and in decreasing working rates of boys. Download Paper
We study the optimal provision of unemployment insurance (UI) over the business cycle. We use an equilibrium search and matching model with aggregate shocks to labor productivity, incorporating risk-averse workers, endogenous worker search effort decisions, and unemployment benefit expiration. We characterize the optimal UI policy, allowing both the benefit level and benefit duration to depend on the history of past aggregate shocks. We find that the optimal benefit is decreasing in current productivity and decreasing in current unemployment. Following a drop in productivity, benefits initially rise in order to provide short-run relief to the unemployed and stabilize wages, but then fall significantly below their pre-recession level, in order to speed up the subsequent recovery. Under the optimal policy, the path of benefits is pro-cyclical overall. As compared to the existing US UI system, the optimal history-dependent benefits smooth cyclical fluctuations in unemployment and deliver substantial welfare gains. Download Paper
We study the effects of changes in uncertainty about future fiscal policy on aggregate economic activity. Fiscal deficits and public debt have risen sharply in the wake of the financial crisis. While these developments make fisscal consolidation inevitable, there is considerable uncertainty about the policy mix and timing of such budgetary adjustment. To evaluate the consequences of this increased uncertainty, we first estimate tax and spending processes for the U.S. that allow for time-varying volatility. We then feed these processes into an otherwise standard New Keynesian business cycle model calibrated to the U.S. economy. We find that fiscal volatility shocks have an adverse effect on economic activity that is comparable to the effects of a 25-basis-point innovation in the federal funds rate. Download Paper
This paper studies the interaction between coordination and social learning in a dynamic regime change game. Social learning provides public information to which players overreact due to the coordination motive. So coordination affects the aggregation of private signals through players' optimal choices. Such endogenous provision of public information results in inefficient herds with positive probability, even though private signals have an unbounded likelihood ratio property. Therefore, social learning is a source of coordination failure. An extension shows that if players could individually learn, inefficient herding disappears, and thus coordination is successful almost surely. This paper also demonstrates that along the same history, the belief convergence differs in different equilibria. Finally, social learning can lead to higher social welfare when the fundamentals are bad. Download Paper
This paper analyzes the theoretical foundations of Giffen goods and details the difficulty with which prior studies have encountered limited empirical proof of Giffenity. Subsequently, a discussion of the economic overview of Russia during the early 1990s is provided. The paper then applies Giffenity to the newly established free market system of post-Soviet Union Russia while acknowledging changes in the prices for goods, specifically, for inferior food commodities. The paper concludes by advocating for the need to incorporate Giffenity into current economic theory to make it more comprehensive. Download Paper
This paper analyzes the causes and implications of recent financial crises. Financial crises in general lead to changes in both theory and practice of economics. The paper takes an historical overview. The global consensus of economic theory during the 20th century is discussed. The paper describes the Bretton Woods regime after World War II, details the era of adaptive expectations and motivates the emerging of the rational expectations school of thoughts. Various perspectives on the causes of the financial crisis are incorporated. The paper provides some policy suggestions and remarks on the consequences of ever-changing capital markets. Download Paper
Theoretical formulations of dynamic heterogeneous-agent economiestypically include a distribution as an aggregate state variable. This paperintroduces a method for computing equilibrium of these models by including a distribution directly as a state variable if it is finite-dimensional or a fine approximation of it if infinite-dimensional. The method accurately computes equilibrium in an extreme calibration of Huffman's (1987) overlapping-generations economy where quasi-aggregation, the accurate forecasting of prices using a small state space, fails to obtain. The method also accurately solves for equilibrium in a version of Krusell and Smith's (1998) economy wherein quasi-aggregation obtains but households face occasionally binding constraints. The method is demonstrated to be not only accurate but also feasible with equilibria for both economies being computed in under ten minutes in Matlab. Feasibility is achieved by using Smolyak's (1963) sparse-grid interpolation algorithm to limit the necessary number of gridpoints by many orders of magnitude relative to linear interpolation. Accuracy is achieved by using Smolyak's algorithm, which relies on smoothness, only for representing the distribution and not for other state variables such as individual asset holdings. Download Paper
This paper examines the where, when and why of first round entrepreneurial investment activity in the United States from the first quarter of 1995 until the second quarter of 2010. The paper analyzes these venture capital investments taking into consideration the role of macroeconomic variables, region, and industry. Additionally, trends in regional and industrial investments are evaluated using statistical and graphical analyses. By studying these findings, we are able to understand the impact of different periods of economic growth on venture capital investments. Lastly, the shock of the bubble and recent financial crisis are integrated into the findings. Download Paper
This paper concerns multistage games, with and without discounting, in which each player can increase the level of an action over time so as to increase the other players’ future payoffs. An action profile is achievable if it is the limit point of a subgame perfect equilibrium path. Necessary conditions are derived for achievability under relatively general conditions. They imply that any efficient profile that is approximately achievable must be in the core of the underlying coalitional game. In some but not all games with discounting, the necessary conditions for achievability are also sufficient for a profile to be the limit of achievable profiles as the period length shrinks to zero. Consequently, in these games when the period length is very short, (i) the set of achievable profiles does not depend on the move structure; (ii) an efficient profile can be approximately achieved if and only if it is in the core; and (iii) any achievable profile can be achieved almost instantly. Download Paper
Bankruptcy laws govern consumer default on unsecured credit. Foreclosure laws regulate default on secured mortgage debt. I investigate to what extent differences in foreclosure and bankruptcy laws can jointly explain variation in default rates across states. I construct a general equilibrium model where heterogeneous infinitely-lived households have access to unsecured borrowing and can finance housing purchases with mortgages. Households can default separately on both types of debt. The model is calibrated to match national foreclosure and bankruptcy rates and aggregate statistics related to household net worth and debt. The model can account for 83% of the variation in bankruptcy rates due to differences in bankruptcy and foreclosure law. I find that more generous homestead exemptions raise the cost of unsecured borrowing. Households in states with high exemptions therefore hold less unsecured and more mortgage debt compared to low exemption states, which leads to lower bankruptcy rates but higher foreclosure rates. The model also predicts recourse results in higher bankruptcy rates and a higher coincidence of foreclosure and bankruptcy. I use the model to evaluate how proposed and implemented changes to bankruptcy policy affect default rates and welfare. The 2005 Bankruptcy Abuse Prevention and Consumer Protection Act yields large welfare gains (1% consumption equivalent variation) but results in increases in both foreclosure and bankruptcy rates. I find that implementing the optimal joint foreclosure and bankruptcy policy, which is characterized by no-recourse mortgages and a homestead exemption equal to one quarter of median income, yields modest welfare gains (0.3% consumption equivalent variation). Download Paper
I structurally estimate an incomplete markets lifecycle model with endogenous labor supply, using data on the joint distribution of wages, hours and consumption. The model is successful at matching the evolution of both the first and second moments of the data over the lifecycle. The key challenge for the model is to generate declining inequality in annual hours worked over the first half of the working life, while respecting the constraints imposed by the data on consumption and wages. I argue that this is a robust feature of the data on lifecycle labor supply that is strongly at odds with the intra-temporal first order condition for labor supply. Allowing for a realistic degree of involuntary unemployment, coupled with preferences that feature nonseparability in the disutility of the extensive and intensive margins of hours worked, allows the model to overcome this challenge. The results imply that labor market frictions are important in jointly accounting for observed cross-sectional inequality in labor supply and consumption and may have quantitative relevance for analyses that exploit the intra-temporal first-order condition for labor. Download Paper