عنوان مقاله [English]
The aim of this paper is to evaluate the effect of income inequality (II) on happiness inequality (HI) in Iran. For this purpose, the literature was reviewed for the relationship between II and HI including income marginal happiness descending, income smoothing theorem and inverted Maslow pyramid of happiness. Then, the factors that affect HI were estimated by means of a threshold regression model during the period of 1973-2014. The estimation results showed that II has a nonlinear and threshold impact on HI. Thus, the Maslow happiness theorem that describes the impact of II on happiness at the top of inverted pyramid was confirmed. In this case, when Gini coefficient is less than 0.416, in the low II regime, an increase in II has a significant negative impact on HI. This is because of being at the bottom of Maslow pyramid. However, after the threshold point, in the high II regime, an increase in II has a significant positive impact on HI because of moving up the pyramid. Therefore, smoothing income in a cross cutter or time series decreases the downward slope of income marginal happiness, which can decrease HI. Based on the results, policymakers are suggested to pay attention to the Gini threshold point of 0.416 to decrease HI. In addition, when II is higher than the threshold level, they can improve happiness distribution with income redistribution policies.