What is the role of transport improvements in globalization? We argue that the nineteenth century is the ideal testing ground for this question: freight rates fell on average by 50% while global trade increased 400% from 1870 to 1913. We estimate the first indices of bilateral freight rates for...

This paper investigates changes in the output and productivity of research and development activities in Japanese manufacturing firms over the 1980s and 1990s. Evidence from aggregate patent and R&D statistics and a micro-level analysis of R&D productivity at the firm-level suggest that there...

We study how exploration versus exploitation innovations impact economic growth through a tractable endogenous growth framework that contains multiple innovation sizes, multi-product firms, and entry/exit. Firms invest in exploration R&D to acquire new product lines and exploitation R&D to...

We construct a model of firm dynamics with heterogeneous productivity and distortions. The productivity distribution evolves endogenously as the result of the decisions of firms seeking to upgrade their productivity over time. Firms can adopt two strategies toward that end: imitation and...