Recovery of causal relationships in data is an essential part of scholarly inquiry in the social sciences. This chapter discusses strategies that have been successfully used in urban and regional economics for recovering such causal relationships. Essential to any successful empirical inquiry is...

Leading empiricists and theorists of cities have recently argued that the generation and exchange of ideas must play a more central role in the analysis of cities. This paper develops the first system of cities model with costly idea exchange as the agglomeration force. Our model replicates a...

This paper revisits the results of Bloom, Schankerman, and Van Reenen (2013) examining the impact of R&D on the performance of US firms, especially through spillovers. We extend their analysis to include an additional 15 years of data through 2015, and update the measures of firms' interactions...

This paper uses a large language model to develop an ex-ante measure of the commercial potential of scientific findings. In addition to validating the measure against the typical holdout sample, we validate it externally against 1.) the progression of scientific findings through a major...

We present quantitative and qualitative evidence (field research) on university technology transfer offices (TTOs). These offices negotiate licensing agreements with firms to commercialize university-based technologies. A stochastic frontier production function framework is used to assess the...

In this paper I develop a positive theory of intergenerational transfers. I argue that transfers are a means to induce retirement. that is, to buy the elderly out of the labor force. The reason why societies choose to do such a thing is that aggregate output is higher if the elderly do not work....

In this paper, we examine one channel through which the trade regime might affect growth in the long run. We model endogenous technological progress that results from profit maximizing investments by far-sighted entrepreneurs. Productivity in the research lab depends upon the "stock of knowledge...

The location of US multinational foreign R&D has shifted significantly to include emerging markets in addition to traditional Western R&D hubs, resulting in two challenges for multinationals: (1) how to transfer knowledge across geographic distances, and (2) how to facilitate learning when local...

I study knowledge spillovers, positive externalities that augment the information set of an economic agent, and reviews the evidence on such spillovers in the context of international economic transactions. Even though spillovers are by their very nature difficult to identify, over recent...

This paper uses wavelets to decompose each stock's trading-volume variance into frequency-specific components. We find that stocks dominated by short-run fluctuations in trading volume have abnormal returns that are 1% per month higher than otherwise similar stocks where short-run fluctuations...