Teaching Historical Research Skills to Undergraduates: Thoughts on Microcomputers and the Classroom

Abstract. In a classic article written in 1994, Robert Fogel assumed that the distribution of calories per head is log normal and that the variance of income per head is greater than the variance of calories per head. Using these assumptions, Fogel was able to conclude that approximately 50 percent of the economic growth since the beginning of the Industrial Revolution is due to changes in nutrition. The author tests those two assumptions with the 1888 cost of living survey (U.S. Department of Labor 1890). Although he finds that the variance of income is greater than the variance of calories per head, distributional tests reveal that the distribution of calories per head is not log normal. In particular, the calorie distribution is skewed to the left, and the tails of the distribution are thicker than those of a log-normal distribution. Graphical tests, however, show that the log-normal assumption is appropriate, and departures from log normality are quite modest. Kernel density estimates further confirm that the distribution of calories per head is approximately log normal. Given the nature of the departures from log normality, Fogel's calculations may understate the role that nutrition has played in economic growth.