We consider an environment in which there is substantial uncertainty about the potential negative external effects of AI algorithms. We find that subjecting algorithm implementation to regulatory approval or mandating testing is insufficient to implement the social optimum. When testing costs...

We propose a model of sovereign debt where countries vary in their level of financial development, defined as the extent to which countries can hedge rare disasters in international capital markets. We show that low levels of financial development generate the "debt intolerance" phenomenon that...

This paper studies how the impact of monetary policy depends on the distribution of savings from refinancing mortgages. We show that the efficacy of monetary policy is state dependent, varying in a systematic way with the pool of potential savings from refinancing. We construct a quantitative...

We study the impact on the skill premium of increases in the quality of goods consumed by households ("trading up"). Our empirical work shows that high- quality goods are more intensive in skilled labor than low-quality goods and that household spending on high-quality goods rises with income....

We study the immigration policy that maximizes the welfare of the native population in an economy where the government designs an optimal redistributive welfare system and supplies public goods. We show that when the government can design different tax systems for immigrants and natives, free...

We argue that the Covid epidemic disproportionately affected the economic well-being and health of poor people. To disentangle the forces that generated this outcome, we construct a model that is consistent with the heterogeneous impact of the Covid recession on low- and high-income people....

We analyze the effects of an epidemic in three standard macroeconomic models. We find that the neoclassical model does not rationalize the positive comovement of consumption and investment observed in recessions associated with an epidemic. Introducing monopolistic competition into the...

Much of the economics literature on epidemics assumes that people know their current health state. Under this assumption, there is no role for testing. To study the general equilibrium e§ects of testing on economic outcomes, we develop a model of epidemics in which people who are not tested are...

We extend the canonical epidemiology model to study the interaction between economic decisions and epidemics. Our model implies that people's decision to cut back on consumption and work reduces the severity of the epidemic, as measured by total deaths. These decisions exacerbate the size of the...

We study how people react to small probability events with large negative consequences using the outbreak of the COVID-19 epidemic as a natural experiment. Our analysis is based on a unique administrative data set with anonymized monthly expenditures at the individual level. We find that older...