This study examines the role of economic institutions in the misery index (the sum of inflation and unemployment rates) across six developing countries (Iran, Turkey, Egypt, Indonesia, Pakistan, and Brazil) during the period 2010–2023, using the New Institutional Economics framework. The study aims to examine the relationship between of institutional variables—including the Corruption Perceptions Index (CPI), trade openness, and the Human Development Index (HDI)—on the misery index, controlling for population, labor force participation rate, and the COVID-19 shock. Panel data were estimated using the fixed effects method. The findings show that, after controlling for country fixed effects, improvements in the CPI (coefficient: -4.88), greater trade openness (-0.21), and higher HDI (-9.52) are significantly associated with a lower misery index, whereas labor force participation (0.45) and the COVID-19 period (5.01) are associated with a higher one. These are conditional correlations and should not be interpreted as causal effects. The results emphasize the need for institutional reforms, particularly reducing corruption, strengthening trade, and investing in education and health in developing countries. Future research is suggested to examine other institutional variables and the effects of sanctions relief.