The received economic wisdom is that cities are too big and that public policy should limit their sizes. This wisdom assumes, unrealistically, that city sites are homogeneous, migration is unfettered, land is given freely to incoming migrants, and federal taxes are neutral. Should those...

Governments frequently intervene to support domestic industries, but a surprising amount of this support goes to ailing sectors. We explain this with a lobbying model that allows for entry and sunk costs. Specifically, policy is influenced by pressure groups that incur lobbying expenses to...

This paper explores the impact of trade on growth when firms are heterogeneous. We find that greater openness produces anti-and pro-growth effects. The Melitz-model selection effects raises the expected cost of introducing a new variety and this tends to slow the rate of new-variety introduction...

A simple model of offshoring, which depicts offshoring as 'shadow migration,' permits straightforward derivation of necessary and sufficient conditions for the effects on wages, prices, production and trade. We show that offshoring requires modification of the four classic international trade...

Tech clusters like Silicon Valley play a central role for modern innovation, business competitiveness, and economic performance. This paper reviews what constitutes a tech cluster, how they function internally, and the degree to which policy makers can purposefully foster them. We describe the...

Our paper integrates results from trade-in-task theory into mainstream trade theory by developing trade-in-task analogues to the four famous theorems (Heckscher-Ohlin, factor price equalisation, Stolper-Samuelson, and Rybczynski) and showing the standard gains-from-trade theorem does not hold...

Melitz (2003) demonstrates that greater trade openness raises industry productivity via a selection effect and via a production re-allocation effect. Our comment points out that the set-up assumed in the Melitz model displays a trade off between static and dynamic efficiency gains. That is,...

Many development policies, such as placement of infrastructure or local economic development schemes, are “place-based.” Such policies are generally intended to stimulate private sector investment and economic growth in the treated place, and as such they are difficult to appraise and...

We develop a methodology to estimate robust city level vehicular mobility indices, and apply it to 154 Indian cities using 22 million counterfactual trips measured by a web mapping service. There is wide variation in mobility across cities. An exact decomposition shows this variation is driven...

A key reason for the existence of cities are the externalities created when people cluster together in close proximity. During Covid, such interactions came with health risks and people found other ways to interact. We document how cities changed during Covid and consider how the persistence of...