Reported rates of return to agricultural R&D are generally high, but they are likely to be biased, particularly because of attribution problems-mismatching research benefits with costs. The importance of attribution biases is illustrated here with new evidence for Brazil. During 1981-2003,...

Replaced with revised version of paper 08/14/07.

In general, reported rates of return to agricultural R&D are high, but questions have been raised about upward biases in the evidence. Among the reasons for this bias, insufficient attention to attribution aspects-matching of research benefits and costs-is a pervasive problem, the magnitude of...

Replaced with revised version of paper 07/10/09.

We use newly constructed state-specific data to explore the implications of common modeling choices for measures of research returns. Our results indicate that state-to-state spillover effects are important, that the research and development lag is longer than many studies have allowed, and that...

Reported rates of return to agricultural R&D are generally high, but they are likely to be biased, particularly because of attribution problems—mismatching research benefits with costs. The importance of attribution biases is illustrated here with new evidence for Brazil. During 1981–2003,...

Annual data for forty-eight states are used to account for changes in the composition of input and output aggregates over space and time, and thereby to obtain new evidence on changes in inputs, outputs, and productivity in U.S. agriculture. The measures change significantly when we use...