As important as productivity growth is to the health of the economy, much remains to be understood about how and why its trend growth rate changes. This Economic Letter discusses some of the points of debate in the research on these issues.

This Economic Letter summarizes the papers presented at the conference "Technological Change," held at the Federal Reserve Bank of San Francisco on November 14-15, 2002, under the joint sponsorship of the Bank and the Stanford Institute for Economic Policy Research. The papers are listed at the...