Some Trade Theorems with a Public Intermediate Good.

This paper considers the implications for the Stolper-Samuelson and Rybczynski theorems of a pure public intermediate good. Necessary and sufficient conditions for the theorems to hold in their strong versions are derived. They show a close formal resemblance to those known from the model with variable returns to scale internal to industries. The dual nature of the two theorems is shown to be preserved. Lastly, sufficiency conditions for either theorem to hold are presented.