Measuring the private returns to R&D requires knowledge of its private depreciation or obsolescence rate, which is inherently variable and responds to competitive pressure. Nevertheless, most of the previous literature has used a constant depreciation rate to construct R&D capital stocks and...

This document describes the panel of publicly traded United States manufacturing firms which was created and updated at the National Bureau of Economic Research from 1978 through 1990 within the Productivity Program. The panel consists of 2726 large manufacturing firms with one to twenty-nine...

What do we know about the relationship between innovation and productivity among firms? The workhorse model of this relationship is presented and the implications of analysis using this model and the usually available data on product and process innovation are derived. The recent empirical...