We present an international trade model with multiproduct firms. Firms are heterogeneously endowed with two types of capabilities that jointly determine the trade-off within firms between managing a large portfolio of products and producing at low marginal cost. The model can explain many of the...

The debate over the use of tariffs or value added taxes in developing countries has focused on the difficulty of collecting VAT from the informal sector of the economy. This paper contributes by considering this issue with heterogeneous firms and endogenous entry. This yields two new results....