This paper examines the effect of technological change and other factors on the relative demand
for workers with different education levels and on the recent growth of U.S. educational wage
differentials. A simple supply-demand framework is used to interpret changes in the relative quantities,
wages, and wage bill shares of workers by education in the aggregate U.S. labor market in each decade
since 1940 and over the 1990 to 1995 period. The results suggest that the relative demand for college
graduates grew more rapidly on average during the past twenty-five years (1970-95) than during the
previous three decades (1940-70). The increased rate of growth of relative demand for college graduates
beginning in the 1970s did not lead to an increase in the college/high school wage differential until the
1980s because the growth in the supply of college graduates increased even more sharply in the 1970s
before returning to historical levels in the 1980s. The acceleration in demand shifts for more-skilled
workers in the 1970s and 1980s relative to the 1960s is entirely accounted for by an increase in within-
industry changes in skill utilization rather than between-industry employment shifts. Industries with large
increases in the rate of skill upgrading in the 1970s and 1980s versus the 1960s are those with greater
growth in employee computer usage, more computer capital per worker, and larger shares of computer
investment as a share of total investment. The results suggest that the spread of computer technology
may "explain" as much as 30 to 50 percent of the increase in the rate of growth of the relative demand
for more-skilled workers since 1970.

Year of Publication
Date Published
Publication Language
Citation Key
Quarterly Journal of Economics, Vol. 113, No. 4, November 1998
Autor, D., Krueger, A., & Katz, L. (1997). Computing Inequality: Have Computers Changed the Labor Market?. Retrieved from (Original work published March 1997)
Working Papers

The slow diffusion of new technology in the agricultural sector of developing countries has long
puzzled development economists. While most of the current empirical research on technology
adoption focuses on credit constraints and learning spillovers, this paper examines the role of
individual risk attitudes in the decision to adopt a new form of agricultural biotechnology in
China. I conducted a survey and a field experiment to elicit the risk preferences of 320 Chinese
farmers, who faced the decision of whether to adopt genetically modified Bt cotton a decade ago.
Bt cotton is more effective in pest prevention and thus requires less pesticides than traditional
cotton. In my analysis, I expand the measurement of risk preferences beyond expected utility
theory to incorporate prospect theory parameters such as loss aversion and nonlinear probability
weighting. Using the parameters elicited from the experiment, I find that farmers who are more
risk averse or more loss averse adopt Bt cotton later. Farmers who overweight small probabilities
adopt Bt cotton earlier.

Year of Publication
Date Published
Publication Language
Citation Key
Liu, E. (2008). Time to Change What to Sow: Risk Preferences and Technology Adoption Decisions of Cotton Farmers in China. Retrieved from (Original work published May 2008)
Working Papers