This dissertation examines the choices of production/marketing strategies used by U.S. multinational corporations (MNCs) in selling and exporting to foreign markets. The varying degree of control a U.S. MNC possesses over its affiliates translates to a varying degree of control it retains over a transaction. A transaction with an unaffiliated firm represents a transaction over which the U.S. MNC has no control; while a transaction with a MOFA represents one over which it has complete control. Transactions with JVs fall in between. Using the shares for unaffiliated parties, MOFAs, and JVs as the three dependent variables, this study tested the empirical relevance of the internalization hypotheses, using both the sales share and the export share model.;The "Amemiya-Tobin" approach of Wales and Woodland was used to estimate the system of share equations. This procedure explicitly builds in the adding-up restriction on shares and allows for the occurrence of zero values for one or two shares in a three-share system. The log likelihood function for the Amemiya-Tobin model was maximized by numerical methods.;Data was collected from the Bureau of Economic Analysis, the Bureau of Census, the World Bank and the Internet (http://www.eiit.org). The final data set was for country-industry pairs, at the loaves, level of industry aggregation available.;The results for the sales share and the export share models show the importance of the internalization hypothesis: R&D expenditure, which served as a proxy for the specialized knowledge of U.S. parent, had a significantly positive impact on MOFA sales and exports to MOFAs. It had a negative impact on the sales and exports to unaffiliated parties. Complementary knowledge of foreign enterprises, which was measured by the number of patent applications filed by the residents of a country, was positively related to the share of sales by joint ventures, and negatively related to the share of sales by MOFAs. However, patent applications did not play a significant role in this model. Importantly, these two results together show the influence of the "ownership of knowledge" in determining the organizational form chosen by U.S. MNCs.