This paper estimates the effect on innovation of increased market access facilitated by trade liberalization. We use a novel empirical design that exploits tariff cuts during the 1990s, along with detailed data on innovation among firms from 65 countries. Our results reveal a large effect of tariff cuts on innovation as measured by patent data, suggesting that multilateral liberalization has promoted innovation and growth. These effects are not driven by the deterioration of innovation quality, and the results are robust to controlling for changes in the patent system and to industry-wide trends in innovation.

We explore firm size heterogeneity in production networks. In comprehensive data for Belgium, firms with more customers have higher total sales but lower sales and lower market shares per customer. Downstream factors, especially the number of customers, explain the vast majority of firm size dispersion. We rationalize these facts with a model of network formation and two-dimensional firm heterogeneity. Higher productivity generates more matches and larger market shares among customers. Higher relationship capability generates more customers and higher sales. Model estimates suggest a strong negative correlation between productivity and relationship capability and potentially large welfare gains from improving relationship capability.