Knowledge that Transforms

We use population data on capital income and wealth holdings for Norway to measure asset positions and wealth returns before individuals marry and after the household is formed. These data allow us to establish a number of novel facts. First, individuals sort on personal wealth rather than parental wealth. Second, people match also on their personal returns to wealth and assortative mating on returns is as strong as that on wealth. Third, post-marriage returns on family wealth reflect in equal part the pre-marriage returns of the two spouses. However, for households at the top of the wealth distribution at marriage, family wealth is largely managed by the spouse with the highest potential to grow it, providing a microfoundation for the scale dependence in wealth returns documented in several empirical papers. Fourth, marriage lowers the degree of wealth inequality as well as the heterogeneity in returns relative to the counterfactual case of no marriages. We use a simple framework to illustrate how the inequality-attenuating role of marriage is affected by assortative mating on wealth and returns and by wealth management task allocation between spouses.

We examine the welfare-based opportunity cost of foreign exchange (FX) intervention when both covered interest rate parity (CIP) and uncovered interest rate parity (UIP) deviations are present. We consider a small open economy that receives international capital flows through constrained international financial intermediaries. Deviations from CIP come from limited arbitrage or through a convenience yield, while UIP deviations are also affected by global risk. We show that the sign of CIP and UIP deviations may differ for safe haven countries. We find that FX reserves may provide a net benefit, rather than a cost, when international intermediaries value the safe-haven properties of a currency more than domestic households. We show that this has been the case for the Swiss franc and the Japanese Yen. We examine the optimal policy of a constrained central bank planner in this context.

This paper investigates the importance of the age composition for pandemic policy design. To do so, it introduces an economic framework with age heterogeneity, individual choice, and incomplete information, emphasizing the value of testing. Calibrating the model to the US Covid-19 pandemic reveals an 80% reduction in the death toll due to voluntary actions and the lockdown implemented in the US. The optimal lockdown, however, is more stringent than what was implemented. Moreover, the social planner follows an asymmetric approach by locking down the young relatively more than the old. We highlight the role of testing in reducing deaths, lowering economic costs, and allowing for a less restrictive lockdown. A social planner would choose a faster ramp-up in testing capacity relative to what occurred in the US. We use the framework to provide insights into pandemics caused by different viruses (including the Spanish flu), and underline the influence of economic conditions on optimal policies.

Motivated by a secular increase in the concentration of the U.S. banking industry, I develop a new macroeconomic model with oligopolistic financial intermediaries and heterogeneous firms. Market power allows banks to price discriminate and charge firm-specific markups, exerting greater market power over productive and more financially constrained firms. This dampens capital accumulation and amplifies the effects of macroeconomic shocks. During a crisis, banks exploit the higher share of financially constrained firms to extract higher markups, inducing a larger decline in real activity. When a large bank fails, the remaining banks use their increased market power to restrict credit supply, worsening and prolonging the downturn.

This paper studies a multi-product monopolist facing a privately informed consumer with additive and type-increasing valuations. Separate monopoly pricing is robustly optimal with respect to the type distribution if and only if the marginal rate of substitution between each pair of goods is monotone. This result is obtained by extending the conventional Myersonian approach.

We study the impact of large, successful manufacturing plants on other local producers in China, focusing on “Million-Rouble Plants” built in the 1950s during a brief alliance with the U.S.S.R. The ephemeral geopolitical situation and the locations of allied and enemy airbases provide exogenous variation in plant siting. We find a boom-and-bust pattern: Counties hosting these plants were 80% more productive than control counties in 1982 but 20% less productive by 2010. This decline reflects the performance of local establishments, which exhibit low productivity, limited innovation, and high markup. Specialization hindered spillovers, preventing the emergence of new clusters and local entrepreneurship.

Racial covenants in housing deeds were widely used in the United States during the early 20th century to segregate neighborhoods. In 1948, the Supreme Court decision in Shelley v. Kraemer made racial covenants unenforceable in court, stopping short of prohibiting them entirely. We surmise that even after losing their judicial enforceability, such covenants could have shaped segregation if they served as a focal point for coordination on an initial equilibrium in neighborhood formation, a context characterized by investment durability and path dependency. To test this hypothesis, we assemble novel parcel-level data on racial covenants and develop a quasi-experimental design that exploits delays between covenant execution and housing construction to isolate exposure to enforceable covenants at the time neighborhoods were built. Covenant enforceability indeed affected early-stage neighborhood formation in terms of housing characteristics, public infrastructure placement, and the composition of initial residents. These early differences proved durable: Enforceable covenants account for 6–24% of the observed neighborhood racial segregation from 1980 to 2020 and 3.1–4.4% of housing price differentials in the 21st century. We conclude that by coordinating beliefs and decisions during neighborhood formation, the law generated spatial inequality that has long outlived racial covenants themselves.

We introduce markup equilibrium—an extension of Walrasian equilibrium in which consumers pay a fixed percentage markup over producer prices. In quasilinear markets, markup equilibria exist despite nonconvexities. They are resource-feasible and envy-free, incur no budget deficit, and require little more communication and computation than ordinary Walrasian equilibrium. The associated markup mechanism is asymptotically incentive-compatible. We also introduce a Bound-Form First Welfare Theorem, which states that for any feasible allocation, the welfare loss compared to the first-best is bounded, using any price vector, by the sum of the resulting (i) budget surplus and (ii) rationing losses suffered by the participants. Using producer prices, this bound implies that any markup equilibrium with a small markup and few unallocated goods is nearly efficient.

I propose a model of skill-replacing routine-biased technological change (SR-RBTC). In this model, technology substitutes for the use of skill in routine tasks, in contrast to standard RBTC models, which assume that technology replaces the workers themselves. The SR-RBTC model explains three key trends that are inconsistent with standard RBTC models: (1) why specifically middle wages declined even though workers in routine occupations are dispersed across the entire bottom half of the wage distribution, (2) why middle wages stopped declining while technological change continued, and (3) why there is no substantial decline in the average wage of workers in routine occupations. I derive two new testable predictions from the model: a decrease in the return to skill and a decrease in skill level in routine occupations. I use an interactive fixed-effects model to confirm both predictions. Since SR-RBTC violates the ignorability assumption required by standard decomposition methods, I introduce a “skewness decomposition” to show that SR-RBTC is the main driver of bottom-half inequality trends.

We study the role of public risk-sharing in markets where firms face substantial cost uncertainty, focusing on public reinsurance in health insurance. We develop a model where insurers internalize cost uncertainty through risk charges that raise effective marginal costs and create a role for reinsurance. Public reinsurance lowers both expected costs and cost volatility, particularly for smaller insurers, reducing prices and enhancing competition. Using an event study of staggered state-level reinsurance programs, we show that public reinsurance leads insurers to lower prices and private reinsurance purchases, benefiting financially constrained insurers the most. Structural estimates indicate that risk charges account for a substantial share of the premium-cost wedge and highlight public reinsurance’s comparative advantage over premium subsidies by providing risk protection and enhancing competition. Our results underscore the importance of accounting for firms’ risk exposure in policy design and provide a general framework for understanding public risk-sharing policies.