There have been many tests of the convergence hypothesis yielding many different estimates of β (the speed of convergence). Narrative reviews of the convergence literature hint at possible reasons for the study-to-study variation in the value of β, but such reviews are selective and informal. In contrast, meta-regression analysis provides a more formal and objective review of the literature. It is shown that study design and methodology are important determinants of the reported convergence rate, especially in cross-national studies. There is also evidence of general misspecification in the literature.