Galtonian Regression across Counties and the Convergence of Productivity.

A Galton model, in logarithmic form, is used to explain the convergence of countries' productivities over time, including beta and sigma convergence. The 'regression fallacy' does not arise. When comparing growths and levels of productivity, countries should be classified by their initial levels of productivity, preferably after logarithmic transformation. Errors in the data may justify using an errors-in-variables model, or the geometric mean of the original and reverse regressions, but this is not certain. Copyright 1995 by Blackwell Publishing Ltd