Knowledge that Transforms

Do workers from social groups with comparable productivity distributions obtain comparable lifetime earnings? We study how a small amount of early-career discrimination propagates over time when workers’ productivity is revealed through employment. In breakdown learning environments that primarily track on-the-job failures, such discrimination spirals into a substantial lifetime earnings gap for groups of comparable productivity, whereas in breakthrough learning environments that track successes, early-career discrimination can be self-corrected, so comparable groups obtain comparable lifetime earnings. This contrast persists in large labor markets and with flexible wages, inconclusive learning, and misspecified employer beliefs.

We study a parsimonious model of a competitive labor market in which firms privately screen workers to identify talent. The equilibrium exhibits dispersion in wages and productivity; when talent is scarce, firms with superior screening skills post higher wages, attract better applicants, and recruit more talented workers. High-wage firms impose a compositional externality on low-wage firms, leading to equilibrium inefficiency: Welfare would be higher if low-skilled firms posted high wages and selected first. We also provide a micro-foundation for firms heterogeneous screening skills. When talented workers are better at screening (e.g. via superior referrals), a dynamic version of the economy converges to a unique steady state in which differences in talent, profits and screening skills persist forever.

This paper studies the unemployment of physical capital—defined as idle units searching to be traded—and its macroeconomic implications. I provide evidence documenting that capital unemployment is large, volatile, and increases during economic downturns. I construct a capital-accumulation model that explains these patterns, with trading frictions in capital markets, which give rise to equilibrium capital unemployment, and financial shocks, which lead to large fluctuations in trading probabilities and capital unemployment. Using the model, I show that trading frictions and capital unemployment matter for aggregate dynamics. First, unemployed capital affects aggregate investment dynamics: Downturns characterized by large increases in unemployed capital are followed by investment slumps, because the economy tends to recover by absorbing existing unemployed capital rather than by producing new capital goods. Second, capital unemployment constitutes a propagation mechanism from financial shocks to economic activity, which shows up at the aggregate level as measured total factor productivity.

We document that the source of funds for paying health insurance premiums has a dramatic impact on plan choices. We focus on the MediSave program in Singapore, a medical savings account that is used to pay out-of-pocket medical spending. Residents can also pay their health insurance premiums with cash or MediSave funds, but are subject to limits that vary by age and over time. By exploiting variations in those limits, we consistently find that when individuals are able to pay their health insurance premiums with MediSave funds, they are less price sensitive and more willing to enroll in more generous plans. We develop and estimate a mental accounting model which explains these patterns. We embed and reject alternative explanations such as hassle costs and liquidity constraints. We then extend this model and show that mental accounting can explain much, but not all, of the misweighting of premiums relative to out-of-pocket expenses in health insurance choice. We also find that allowing MediSave payment for both premiums and out-of-pocket expenses (e.g. putting them in the same mental account) enhances individual welfare and reduces adverse selection.

University access has significantly expanded in OECD countries, and further growth figures prominently in political agendas. We study possible consequences of historical and future expansions in a stochastic, general equilibrium Roy model where tertiary educational attainment is determined by cognitive ability and socioeconomic disadvantage. In our analysis, individual productivity depends not only on education but also directly on cognitive ability. The expansion of university access in the U.K. that started in the 1960s provides an ideal case study to draw lessons for the future. We find that this expansion led to the selection into college of progressively less talented students from advantaged backgrounds. Appropriate counterfactual policies existed that would have achieved the dual goal of increasing college graduates’ cognitive ability while improving tertiary education opportunities for the disadvantaged.

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.

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.

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.

We consider an oligopoly model in which each firm chooses not only its price but also its advertising strategy regarding how much, and what, product information to provide. To highlight firms’ strategic incentives, we impose no structural restrictions on feasible advertising content, so that each firm can disclose or conceal any information. We obtain a comprehensive characterization of the equilibrium advertising strategy and provide some sufficient conditions for the existence of symmetric pure-price equilibria. We show that intense competition induces firms to provide accurate product information; firms usually obfuscate consumers’ relatively low or high values; and requiring firms to provide more product information can reduce social surplus and also be harmful to consumers.

We study the labour market effects of permanent 30%–64% reductions on unemployment insurance benefits available in seven states. Leveraging linked firm-establishment data, we find that establishments based on reform states experience employment increases that are 0.8%–1.3% larger than those of the same firm’s establishments in other states. Using a similar multi-state firm design, starting salaries are 1.2%–5.5% lower in reform states and posted salaries for the same job fall by 3.2%–3.5%. The negative co-movement of employment and wages after the reform suggests a labour supply shock and mitigates against confounding changes in labour demand driving the results. Our findings are consistent with workers lowering their reservation wages as outside options fall, and employers take advantage of this by offering lower wages and increasing employment.