This paper examines the empirical cross-sectional dynamics of economic growth, challenging the assumption that economies converge to a steady-state growth path. Using data on 118 countries, the author finds that long-run growth patterns are unstable, with significant changes in growth trends and income variability over time. Cross-country regressions that assume a steady-state growth path fail to capture these dynamics, as evidenced by the increasing variability in income levels and growth rates. The author proposes an alternative econometric approach that models the evolution of income distributions over time, using a Markov chain transition matrix to capture the dynamics of cross-sectional income changes. This approach reveals that incomes tend to concentrate at the extremes—either very high or very low—over the long run, with persistence in income levels and limited mobility. Growth rates, in contrast, show more cross-sectional mobility and less persistence. The paper concludes that economic growth is a dynamically evolving process, with significant differences in income distribution across countries, and that traditional models of convergence may not fully capture these dynamics. The author suggests that further research is needed to better understand the mechanisms driving these patterns and to develop more accurate models of economic growth.This paper examines the empirical cross-sectional dynamics of economic growth, challenging the assumption that economies converge to a steady-state growth path. Using data on 118 countries, the author finds that long-run growth patterns are unstable, with significant changes in growth trends and income variability over time. Cross-country regressions that assume a steady-state growth path fail to capture these dynamics, as evidenced by the increasing variability in income levels and growth rates. The author proposes an alternative econometric approach that models the evolution of income distributions over time, using a Markov chain transition matrix to capture the dynamics of cross-sectional income changes. This approach reveals that incomes tend to concentrate at the extremes—either very high or very low—over the long run, with persistence in income levels and limited mobility. Growth rates, in contrast, show more cross-sectional mobility and less persistence. The paper concludes that economic growth is a dynamically evolving process, with significant differences in income distribution across countries, and that traditional models of convergence may not fully capture these dynamics. The author suggests that further research is needed to better understand the mechanisms driving these patterns and to develop more accurate models of economic growth.