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...

Initial inequality in endowments and opportunities, together with low average levels of endowments, can create constituencies in a society that combine to paralyze reforms, even though the status quo hurts them collectively. Each constituency prefers reforms that expand its opportunities, but in...

Structurally estimating the Grossman and Helpman (1994) model using coverage ratios that include non-tariff barriers leads to biased parameter estimates. We develop a "protection for sale" theoretical framework consistent with the data, by explicitly allowing for non-tariff barriers. Introducing...

This paper reviews the economics approach to conflict and national borders. The paper provides a summary of ideas and concepts from the economics literature on the size of nations; illustrates them within an analytical framework where populations engage in conflict over borders and resources,...

Although most disputes between groups of people are settled peacefully, sometimes disputes result in war. This lecture uses historical examples to illustrate how the ability to negotiate a credible peaceful settlement of a dispute between sovereign states, typically a dispute over the control of...

We develop a measure of a regime's tolerance for an action by its citizens. We ground our measure in an economic model and apply it to the setting of political protest. In the model, a regime anticipating a protest can take a costly action to repress it. We define the regime's tolerance as the...

We show that grandfathering fishing rights to local users or recognizing first possessions is more dynamically efficient than auctions of such rights. It is often argued that auctions allocate rights to the highest-valued users and thereby maximize resource rents. We counter that rents are not...