In this paper we analyze the evidence from a large number of studies on three specific questions pertaining to R&D investment: (1) Are there diminishing returns to inventive activities? (2) What is the relationship between R&D and productivity and what are the magnitudes of the returns to a...

This paper studies vertical R&D spillovers between upstream and downstream firms. The model incorporates two vertically related industries, with horizontal spillovers within each industry and vertical spillovers between the two industries. Four types of R&D cooperation are studied: no...