We develop a product-differentiated model where the product space is a network defined as a set of varieties (nodes) linked by their degrees of substitutability (edges). We also locate consumers into this network, so that the location of each consumer (node) corresponds to her "ideal" variety....

Utilizing panel data for 19 OECD countries we find suppor t for the hypothesis that a greater degree of product variety relative to the US helps to explain relative per capita GDP levels. The empirical work relies upon some direct measures of product variety calculated from 6-digit OECD export...

In a free-entry Cournot oligopoly model with a quadratic utility function that yields differentiated products, it is shown that there are losses from trade when the trade cost is close to the prohibitive level. Although the total number of varieties increases, there is a reduction in consumer...