Using detailed U.S. and Spanish export data, we document that trade costs of a per-shipment nature are associated with less frequent and larger shipments (i.e., more lumpiness) in international trade. This finding is pervasive across broad product categories, but most apparent for industrial supplies, parts and accessories, and food products.

We use variation from the minimum legal drinking age to estimate the causal effect of access to alcohol on crime. Using a census of arrests in California and a regression discontinuity design, we find that individuals just over age 21 are 5.9% more likely to be arrested than individuals just under 21. This increase is mostly due to assaults, alcohol-related offenses, and nuisance crimes. These results suggest that policies that restrict access to alcohol have the potential to substantially reduce crime.

In direct contrast to conventional wisdom and most economic models of marital age gaps, we present robust evidence that men and women who are married to differently aged spouses are negatively selected. Empirical results show lower cognitive ability, lower educational attainment, lower occupational wages, lower earnings, and less attractive appearance among those married to a differently aged spouse. These results, obtained using samples of first marriages and controlling for age of marriage, are consistent with a model in which individuals with more schooling and more upwardly mobile occupations interact more heavily with similarly aged peers and are ultimately more likely to marry similarly aged spouses.

This note proposes a new decomposition of average treatment effects on nonnegative outcomes. It represents the total effect as a population-weighted sum of the effects for two groups: those induced to participate by the treatment and those participating regardless of it. The usual decomposition into extensive and intensive margins used in the literature is generally incompatible with such a causal interpretation. The difference between decompositions can be substantial and yield diametrically opposed results.

This paper introduces a new confidence interval (CI) for the autoregressive parameter (AR) in an AR(1) model that allows for conditional heteroskedasticity of a general form and AR parameters that are less than or equal to unity. The CI is a modification of Mikusheva's (2007a) modification of Stock's (1991) CI that employs the least squares estimator and a heteroskedasticity-robust variance estimator. The CI is shown to have correct asymptotic size and to be asymptotically similar (in a uniform sense). It does not require any tuning parameters. No existing procedures have these properties. Monte Carlo simulations show that the CI performs well in finite samples in terms of coverage probability and average length, for innovations with and without conditional heteroskedasticity.

We investigate the 2008–2009 trade collapse using microdata from a small open economy, Belgium. Belgian exports and imports mostly fell because of smaller quantities sold and unit prices charged rather than fewer firms, trading partners, and products being involved in trade. Our difference-in-difference results point to a fall in the demand for tradables as the main driver of the collapse. Finance and involvement in global value chains played a minor role. Firm-level exports-to-turnover and imports-to-intermediates ratios reveal a comparable collapse of domestic and cross-border operations. Overall, our results reject a crisis of cross-border trade per se.

The migration of young Chinese scientists to undertake graduate studies in U.S. universities is arguably one of the most important recent episodes of skilled migration. Using a new data set covering around 16,000 Ph.D. graduates in 161 U.S. chemistry departments, we show that Chinese students have a scientific output during their thesis that is significantly higher than other students. In fact, conditional on acceptance into the same programs, Chinese students perform about as well as the awardees of the NSF doctoral fellowship program. These results shed new light on the benefits of student migration on scientific productivity of destination countries.

Pension benefit guarantees have been introduced in several countries to protect private plan members from the loss of income associated with the termination of an underfunded plan. Most such schemes face financial difficulty. Consequently, policy reforms are being contemplated. Economic theory suggests that such schemes will suffer moral hazard problems. We test a specific theoretical prediction: insured plans will invest more heavily in risky assets. Our test exploits policy differences across Canadian jurisdictions. We find that insured plans invest about 5% more in equities than do similar plans without benefit guarantees.

This paper quantifies trade policy changes and the associated trade impacts for about 100 countries between 2008 and 2009. Results show that there has been no widespread increase in protectionism. Only a few countries, including Russia, Argentina, Turkey, and China, have increased tariffs on major imported products. The United States and the EU, by contrast, rely mainly on antidumping duties to shield domestic industries. Overall, while the rise in tariffs and antidumping duties may have jointly caused global trade to drop by US$43 billion, it explains less than 2% of the collapse in world trade during the crisis period.

Nonparametric estimators of treatment effects are often applied in settings where clustering may be important. We provide a general methodology for consistently estimating the variance of a large class of nonparametric estimators, including the simple matching estimator, in the presence of clustering. Software for implementing our variance estimator is available in Stata.

This paper studies the relationship between height and leadership. Using data from a representative sample of Swedish men, I document that tall men are significantly more likely to attain managerial positions. An increase in height by 10 centimeters (3.94 inches) is associated with a 2.2 percentage point increase in the probability of holding a managerial position. Selection into managerial positions explains about 15% of the unconditional height-wage premium. However, about half of the height-leadership correlation is due to a positive correlation between height and cognitive and noncognitive ability.

We compare the finite-sample performance of impulse response confidence intervals based on local projections (LPs) and vector autoregressive (VAR) models in linear stationary settings. We find that in small samples, the asymptotic LP interval often is less accurate than the bias-adjusted bootstrap VAR interval, notwithstanding its excessive average length. Although the asymptotic LP interval has adequate coverage in sufficiently large samples, its average length still far exceeds that of bias-adjusted bootstrap VAR intervals with comparable accuracy. Bootstrap LP intervals (with or without bias correction) and asymptotic VAR intervals are shorter on average, but they often lack coverage accuracy in finite samples.

Careful examination of the structure determining treatment choice and outcomes, as advocated by Heckman (2008), is central to the design of treatment effect estimators and, in particular, proper choice of covariates. Here, we demonstrate how causal diagrams developed in the machine learning literature by Judea Pearl and his colleagues, but not so well known to economists, can play a key role in this examination by using these methods to give a detailed analysis of the choice of efficient covariates identified by Hahn (2004).

We analyze the effect of survey design on reported job satisfaction by exploiting two quasi-experiments in the British Household Panel Survey: a change in question design and parallel use of different interview modes. We show that apparently minor differences in survey design lead to substantial biases in econometric results, particularly on gender differences. The common empirical finding that women care less about wages and prefer to work fewer hours than men appears largely an artifact of survey design rather than a true behavioral difference.

Previous empirical literature has found a sharp decline in consumption during the first years of retirement, implying that individuals do not save enough for their retirement. This phenomenon is called the retirement consumption puzzle . We find no evidence of the retirement consumption puzzle using panel data from 1980 to 2000. Consumption is defined as nondurable expenditure, a more comprehensive measure than only food used in many of the previous studies. We find that food expenditure declines at retirement, which is consistent with previous studies.

This paper provides evidence on the patterns of multiproduct firm production in a large developing country, India, during a period that spans market reforms. In the cross-section, multiproduct firms in India look remarkably similar to their U.S. counterparts. The time-series patterns, however, exhibit important differences. In contrast to evidence from the United States, product churning, particularly product rationalization, is far less common in India. We find no link between product rationalization and output tariff declines following India's 1991 trade liberalization. The lack of “creative destruction” is consistent with the role of industrial regulation in preventing an efficient allocation of resources.

Previous research has interpreted the correlation between per capita income and civil war as evidence that poverty is a main determinant of conflict. In this paper, we find that the relationship between poverty and civil war is spurious and is accounted for by historical phenomena that jointly determine income evolution and conflict. In particular, the statistical association between poverty and civil wars disappears once we include country fixed effects. Also, using cross‐section data for 1960 to 2000, we find that once historical variables like European settler mortality rates and the population density in 1500 are included in civil war regressions, poverty does not have an effect on civil wars. These results are confirmed using longer time series from 1825 to 2000.

It has long been hypothesized that individuals' migration propensities depend on their risk attitudes, but the empirical evidence has been limited and indirect. We use newly available data from the German Socio-Economic Panel to measure directly the relationship between migration and risk attitudes. We find that individuals who are more willing to take risks are more likely to migrate. Our estimates are substantial compared to unconditional migration probabilities, as well the effects of conventional determinants of migration, and are robust to controlling for a variety of demographic characteristics. We find no evidence that our results are the result of reverse causality.

Consumption growth is predictable, a basic violation of the permanent-income hypothesis. This paper examines three possible explanations: rule-of-thumb behavior, in which households allow consumption to track per period income flows rather than permanent income; habit persistence; and nonseparability in preferences over consumption and leisure. The results illustrate that weak instruments make the results highly sensitive to some arbitrary choices common in the literature. Using a technique that is robust to instrument choice, the analysis shows support for habit persistence and rule-of-thumb behavior and little support for nonseparability between consumption and leisure.

We study strategic choice of effort in best-of-three contests between equally skilled players. Economic theory predicts such contests are more likely to end in two rounds than in three. If, however, a contest reaches a third round, each player is equally likely to win. We test these predictions with data from professional tennis matches, using betting odds to identify equally skilled opponents. The empirical results support the theoretical predictions, suggesting players strategically adjust efforts during a best-of-three contest.