Recent theories of economic growth, including Romer (1986), Porter (1989) and Jacobs (1969), have stressed the role of technological spillovers in generating growth. Because such knowledge spillovers are particularly effective in cities, where communication between people is more extensive, data...

The Coase theorem implies that, in a world of positive transaction costs, any of a number of strategies, including judicially enforced private contracts, judicially enforced laws, or even government regulation, may be the cheapest way to bring about efficient resource allocation. Unfortunately,...

We review the fast-growing work on salience and economic behavior. Psychological research shows that salient stimuli attract human attention "bottom up" due to their high contrast with surroundings, their surprising nature relative to recalled experiences, or their prominence. The Bordalo,...

Although recent research suggests that intergenerational transfers play an important role in aggregate capital accumulation, our understanding of bequest motives remains incomplete. We develop a simple model of"exchange-motivated" bequests, in which a testator influences the decisions ofhis...

This paper discusses two simple decompositions for aggregate productivity analysis in the presence of distortions and in general equilibrium. The first is a generalization of Baqaee and Farhi (2017) and the second is due to Petrin and Levinsohn (2012). In the process, we propose a new...

We introduce diagnostic expectations into a standard setting of price formation in which investors learn about the fundamental value of an asset and trade it. We study the interaction of diagnostic expectations with two well-known mechanisms: learning from prices and speculation (buying for...

How does an increase in the size of the market due to fertility, immigration, or trade integration, affect welfare and real GDP? We study this question using a model with heterogeneous firms, fixed costs, and monopolistic competition. We decompose the change in welfare into changes in technical...

A tension between entry and rents lies at the core of a general theory of aggregation with scale effects. This paper characterizes the responses of macro aggregates to micro shocks in disaggregated economies with general forms of entry, internal or external returns to scale, input-output...

We study supply and demand shocks in a general disaggregated model with multiple sectors, multiple factors, input-output linkages, downward nominal wage rigidities, credit-constraints, and a zero lower bound. We use the model to understand how the Covid-19 crisis, an omnibus of supply and demand...

This paper analyzes the possibility and the consequences of rational bubbles in a dy- namic economy where financially constrained firms demand and supply liquidity. Bub- bles are more likely to emerge, the scarcer the supply of outside liquidity and the more limited the pledgeability of...