This paper investigates the long-run convergence of per capita output across OECD members and some emerging countries from 1953 to 2019. To confirm the existence of output convergence toward the reference country (the US), several unit root testing methods are employed. Moreover, to find possible growth determinants to promote convergence, some stationary covariates for the tests are used. In addition, the approach allows for the presence of endogenous structural breaks in the time series under investigation, to capture sharp drops in per capita outputs, which may be brought about by influential economic events such as serious economic slumps in domestic economies or the global financial crises. We also examine whether some institutional factors help to hold the convergence hypothesis.