An inquiry into the causes of income differences among high-income countries

Within high-income countries, there is a notable income inequality spectrum, with certain nations positioned close to a predefined economic threshold, while others within this cohort simultaneously embark on substantial economic growth. This study investigates the influence of critical factors on economic growth and the transition from lower-high and middle-high income to upper-high income. Between 1990 and 2019, 25 of the 28 nations successfully advanced to upper-high income levels. Several key factors contribute to overcoming the barriers associated with lower-high income or middle-high income to upper-high income status. These factors include labor force participation, labor productivity, life expectancy, high-tech exports, reduction in unemployment rates, age dependency ratio, and poverty. The regression discontinuity analysis reveals a positive impact on the experimental group, as economic globalization surpasses the threshold of 78 % facilitating the achievement of upper-high income status.