The objective of this dissertation is to examine multi-product firms' productivity and export behavior. More specifically, this dissertation estimates productivity of firms that produce and sell multiple products, and the role of productivity in such firms' export behavior. In doing so, this dissertation develops a firm-level gravity approach to test whether multi-product firms self select to export or learn from exporting.
In the first of part of this dissertation, I examine whether intra-firm resource reallocation of a multi-product firm affects its Total Factor Productivity (TFP). By extending earlier approaches, I estimate unbiased and consistent TFP of multi-product firms using a revenue-based production function. I find that TFP is more likely to be overestimated when multi-product firms' internalized demand linkage is not taken into account. I also find that multi-product firms' TFP decreases as it expands the number of products produced, but specialization of production does not play a role in TFP.
In the second part, I present a theoretical framework to derive a firm-level gravity equation. By equating the total demand and total production of multi-product firms, I
derive a firm-level gravity equation where export flows from firms to consumers is proportional to the product of economic size of firms, consuming power of a representative consumer, and trade resistance between origin and destination. Using the firm-level gravity equation, I test the hypothesis that high productivity firms self select to export and that the size of export flows is determined by productivity. I find that the economic size of exporting firms and the consuming power of a representative consumer have a positive and statistically significant effect on exports, while trade resistance such as tariff and distance have the opposite effect. I also find that the estimated coefficients of the firm-level gravity equation tend to be smaller than those of the traditional country-level gravity equation.
In the final part of the dissertation, I test whether or not previous export experience improves the productivity of firms. Again, the estimable equation is derived from the equilibrium condition presented in the second part. My result confirms that previous export experience indeed improves productivity of exporting firms, but tariffs have the opposite effect.
The results of this dissertation reveal the economic behavior of multi-product firms, which usually account for a large of economic activity and output in many countries. Understanding such firms' productivity and export behavior can offer strategies for economic growth and development. Empirical findings of this dissertation suggest policy options including lowering tariffs, and improving infrastructure that can lower transportation costs. Further examination of product range and specialization of production can offer strategies to source exports from small and midsize firms.