"How Fast Do Old Men Slow Down?" The Review of Economics and Statistics, 1994.Paper: pdf file
An important question in the study of aging concerns the rate at which people physically deteriorate with age. How much, for example, can be physically expected of, say, a healthy, non-injured 75-year-old man or woman relative to what he or she could do at age 45? This paper applies econometric techniques to data on men's track and field and road racing records by age to estimate the rate at which men slow down with age. Eight track, eight field, and eleven road racing events are considered. The main econometric technique used is a combination of the polynomial-spline method and the frontier-function method. A number of the events have been pooled to provide more efficient estimates.
This is the first paper I did on aging. For the complete list of papers see Papers on Aging.