Knowledge that Transforms

Wealth inequality has prompted calls for higher taxes on capital income and wealth but also concerns that rich households would respond by concealing their assets offshore. We use a general equilibrium model to study how taxing capital more heavily would affect offshore tax evasion and how this would affect the broader economy. Without evasion, tax revenue could be increased dramatically, inequality could be reduced, and widespread welfare gains could be achieved. After accounting for evasion, however, tax revenue would rise marginally or even fall, inequality would increase, and widespread welfare losses would result.

In a paper published in the Journal of Political Economy, Carneiro, Løken, and Salvanes (2015) reported large positive effects on offspring outcomes of a reform they described as introducing paid maternity leave in Norway. Causal identification rested on a discontinuity implying that only mothers giving birth after a specific cutoff date were entitled to paid leave. We show that the analysis relied on an incorrect description of the reform. The reform did not introduce paid maternity leave, but extended it by 5–6 weeks. The postulated discontinuity never existed as treatment and control groups had the same maternity leave conditions.

We build a bridge between relationship lending and transactions lending—investigating relationship effects on contract terms for credit cards, a relatively pure transactions-lending technology. Using more than 1 million accounts, we find that during normal times, consumers with relationships obtain better terms but small businesses with relationships do not. Both groups obtain improved terms during COVID-19, consistent with intertemporal smoothing—relationship borrowers obtain more favorable terms during crises, paid for by worse terms in normal times. Among other findings, CARES Act impediments to reporting consumer delinquencies to credit bureaus, designed to protect customers, reduced informational value of credit scores, penalizing safer consumers.

We investigate whether older people correctly perceive their cognitive decline and the potential financial consequences of misperception. First, we show that older people tend to underestimate their cognitive decline. We then show that those experiencing a severe decline but unaware of it are more likely to suffer wealth losses. These losses largely reflect decreases in financial wealth and are mainly experienced by wealthier people who were previously active on the stock market. Our findings support the view that financial losses among older people unaware of their cognitive decline are the result of bad financial decisions, not of rational disinvestment strategies.

How do elite universities balance diversity and academics during admissions? We develop a theory-based empirical framework to identify and quantify this potential trade-off, using postentry outcomes. We apply this to matched admission and exam-performance data from Cambridge. Comparing first- versus second-round admits from different demographic groups yields bounds on the trade-off magnitude, which (a) hold irrespective of whether we observe all applicant characteristics and (b) require no information on rejected applicants. We find robust evidence of trade-off between gender balance and future performance in math-intensive subjects but not for state/private school students or for gender in competitive nonmathematical disciplines.

We explore the evolution of financial innovation using US finance patents. Patented financial innovations are substantial and increasingly economically important. Their subject matter has changed, consistent with the industry’s shift toward household investors and borrowers. Information technology (IT) and other nonfinancial firms drove the surge in financial patenting. The location of innovation shifted, with banks moving activity away from states with tight financial regulation and high-tech regions attracting innovation by payments, IT, and nonfinancial firms. Analyses of returns suggest that the social value of these innovations is higher than their private value. We present a simple model to explain these trends.

We examine aggregate economic gains in the United States as the railroad network expanded in the nineteenth century. Using data from the Census of Manufactures, we estimate relative increases in county aggregate productivity from relative increases in county market access. In general equilibrium, we find that the railroads substantially increased national aggregate productivity. By accounting for input distortions, we estimate much larger aggregate economic gains from the railroads than previous estimates. Our estimates highlight how broadly-used infrastructure or technologies can have much larger economic impacts when there are inefficiencies in the economy.

As millions of soldiers deployed to Iraq or Afghanistan between 2001 and 2021, Veteran Affairs Disability Compensation payments quadrupled and the veteran suicide rate rose rapidly. We estimate the causal contribution of combat deployments to declining veteran well-being. Deployments increase injuries, combat deaths, and disability compensation, but we find limited effects on suicide, deaths of despair, financial health, incarceration, or education. Our estimates suggest that deployment cannot explain either the recent rise in disability payments, which is more likely driven by policy changes, or the surge in noncombat deaths, which is better explained by shifts in observable characteristics of soldiers.

Throughout the twentieth century, the relationship between women’s human capital and men’s income was nonmonotonic: while college-educated women married richer spouses than high school–educated women, graduate-educated women married poorer spouses than college-educated women. This can be rationalized by a bidimensional matching framework where women’s human capital is negatively correlated with another valuable trait: fertility, or reproductive capital. Such a model predicts nonmonotonicity in income matching with a sufficiently high income distribution of men. A simulation of the model using US Census fertility and income data shows that it can also predict the recent transition to more assortative matching as desired family sizes have fallen.

I analyze a reputation game between a patient player and a sequence of short-run players. Each short-run player observes the number of times that the patient player took each of his actions in the past K periods. When players have monotone supermodular payoffs, the patient player can approximately secure his commitment payoff in all equilibria regardless of K. I also show that the short-run players can approximately attain their highest feasible payoff in all equilibria if and only if K is lower than some cutoff. This is because a larger K weakens the short-run players’ incentives to punish the patient player.