"We use firm-level data for U.S. multinational enterprises (MNE) and the model of firm heterogeneity first presented in Helpman, Melitz, and Yeaple (2004) to make four empirical contributions. First, we show that the most productive U.S. firms invest in a larger number of foreign countries and...

The objective of this study is to investigate the sensitivity of the estimated relationship between innovation and firm performance. In doing so, we rely on a knowledge production function approach and carry out comparisons in a number of respects. The sensitivity analysis is based on the...

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...