This paper generalizes the standard habit formation model to an environment in which agents form habits over individual varieties of goods as opposed to over a composite consumption good. We refer to this preference specification as `deep habit formation'. Under deep habits, the demand function...

We study habitual brand loyalty, one of the earliest empirically-studied forms of switching costs and a classic source of structural state-dependence in consumer demand. Auxiliary instruments and economically-motivated restrictions can tighten nonparametric bounds on the extent of brand loyalty...

We identify novel technologies using textual analysis of patents, job postings, and earnings calls. Our approach enables us to identify and document the diffusion of 29 disruptive technologies across firms and labor markets in the U.S. Five stylized facts emerge from our data. First, the...

This paper models the adoption by established firms of technologies that are internally disruptive in that different parts of an organization stand to lose or gain from adoption. When agents disagree with a decision they impose costs on the firm. The paper shows that any resistance to change...

This paper reviews the main motivations and arguments of my work on comparative development, colonialism and institutional change, which was often carried out jointly with James Robinson and Simon Johnson. I then provide a simple framework to organize these ideas and connect them with my...

A recent literature has developed that combines two prominent empirical approaches to ex ante policy evaluation: randomized controlled trials (RCT) and structural estimation. The RCT provides a "gold-standard'' estimate of a particular treatment, but only of that treatment. Structural estimation...

The trend towards giving consumers choice about their health plans has invited research on how good they actually are at making these decisions. The introduction of Medicare Part D is an important example. Initial plan choices in this market were generally far from optimal. In this paper, we...

This paper uses an open economy DSGE model to explore how trade openness affects the transmission of domestic shocks. For some calibrations, closed and open economies appear dramatically different, reminiscent of the implications of Mundell-Fleming style models. However, we argue such stark...

This paper investigates the role of product upgrades and consumer switching costs in the tying of complementary products. Previous analyses of tying have found that a monopolist of one product cannot increase its profits and reduce social welfare by tying and monopolizing a complementary product...