This study uses data on men's track and field and road racing records by age to estimate the rate at which men slow down with age. For most of the running events (400 meters through the half marathon), the slowdown rate per year is estimated to be .80 percent between ages 35 and 51. At age 51...

Age effects in baseball are estimated in this paper using a nonlinear fixed-effects regression. The sample consists of all players who have played 10 or more "full-time'' years in the major leagues between 1921 and 2004. Quadratic improvement is assumed up to a peak-performance age, which is...

This paper uses world running records by age to estimate a biological frontier of decline rates. Two models are compared: a linear/quadratic (LQ) model and a non-parametric model. Two estimation methods are used: 1) minimizing the squared difference between the observed records and the modeled...