We use transaction-level data to study changes in the concentration of US imports. Concentration has fallen in the typical industry, while it is stable by industry and origin country. The fall in concentration is driven by the extensive margin: the number of exporting firms has grown, and the...

Knowledge exchange, innovation policy, and international trade flows are key aspects of the knowledge-based economy. In her introduction to the special issue on The Knowledge-Based Society: Transition, Geography, and Competition Policy the author briefly reviews these aspects. She begins with...

This paper revisits the home market effect (HME) without any homogeneous good by reconstructing the footloose capital model. This simple model analytically reproduces some typical results scattered in the existing literature, and also provides new insights. Firstly, we derive both spatial...

The paper tests the role of agglomeration effects on the export decision of services firms. Recent theories on trade with heterogeneous firms predict that export participation goes along with sunk market-entry costs. Only the more productive firms will be able to overcome these sunk costs. This...

In the analysis of bilateral trade flows, reported trade of zero or missing observations are quite common and this is a problem when estimating log-linear gravity equations. This has caused many researchers to either ignore the zero trade flows or to replace the zero with a small positive...

Trade costs are crucial in new economic geography (NEG) models. The unavailability of actual trade costs data requires the approximation of trade costs. Most NEG studies do not deal with the ramifications of the particular trade costs specification used. This paper shows that the specification...

It has become common to measure the quality of exports using their unit export value (UEV). Applications of this method include studies of intra-industry trade (IIT) and analyses of industrial "competitiveness". This literature seems to assume that export quality and export price (the most...

Helpman, Melitz and Rubinstein (2008) derive gravity equations to estimate effects of trade barriers on the intensive and extensive margins of trade. They exploit the frequency of zeros in aggregate bilateral trade data to identify effects on the extensive margin and to obtain controls for firm...

We investigate the effect of better access to foreign markets on innovation strategies of multi-product firms in industries with different scope for product differentiation. Industry-specific demand and cost linkages induce a distinction between the returns to innovation. In differentiated...

Gravity equations have been used for more than 50 years to estimate ex post the partial effects of trade costs on international trade flows, and the well-known - and traditionally presumed exogenous - "trade-cost elasticity" plays a central role in computing general equilibrium trade-flow and...