Volume 40, Issue 4 Convergence or confusion? A study of world economic growth Keunkwan Ryu Seoul National University Yong Yoon Chulalongkorn University Abstract This paper takes a closer look at the typical growth convergence regression of Barro (1991), Mankiw, Romer and Weil (1992), Sala-i-Martin (1996), and others. By interpreting the two components of the regression coefficient separately, i.e. the correlation coefficient and the ratio of standard deviations, we distinguish between "time-series" convergence and "cross-section" convergence, and consequently the relationship between β− and σ−convergence. And, using data from the latest Penn World Table database (version 9.1), we investigate the convergence or the lack- of-convergence in samples of countries representing the “World”, OECD and Sub-Saharan Africa. The implications of this study for the neoclassical growth model are also discussed. Citation: Keunkwan Ryu and Yong Yoon, (2020) ''Convergence or confusion? A study of world economic growth'', Economics Bulletin, Volume 40, Issue 4, pages 2819-2827 Contact: Keunkwan Ryu - ryu@snu.ac.kr, Yong Yoon - yong.y@chula.ac.th. Submitted: August 11, 2019. Published: October 12, 2020.