Due to a rise in the ageing population, the upper-middle-income economies might not be able to embrace the fourth industrial revolution, thus limiting their ability to achieve highincome economies. This paper aims to investigate how the increase in the ageing population affects the economic growth of the 32 countries in the upper-middle-income economies from 1990 to 2018. By employing system GMM, the finding shows that the ageing population does adversely affect the economic growth of the upper-middle-income economies as outlined by the theory of secular stagnation. This finding requires special attention for the governments to redesign their fiscal policy by focusing on higher budget allocation on education and critical sectors. It is with a hope that the long-term growth will increase eventually even when the countries are facing a rise in the ageing population. Future researchers may extend this study by examining how ageing population affect the public debt of a country.