Estimation the Sustainable Welfare Index (SWI) In Iran and Investigation of Threshold Effects of Factors Affecting SWI Using Smooth Transition Regression Model

In this study, a new composite index, called the SWI (Sustainable Welfare Index) is proposed to assess "sustainable welfare". This index consists of significant social, economic, and environmental variables in flow and monetary forms, and can be directly compared to the GDP. Despite the paucity of statistical data, an attempt has been made to make a relative assessment of sustainable welfare in the Iranian economy during the years 2004 to 2018. According to the comparison of calculated SWI with GDP, it has been shown that the two indicators have similar movements and higher correlations in the period under study. In addition, despite the availability of economic growth during the period, society has been below a sustainable welfare level. In this study, the threshold effect of three SWI sub-indices on the total index was assessed using the smooth transition regression (STR) Model. As a result, the sub-index "Social Expenditure" through changes in "welfare losses due to income inequality" is of threshold effect on SWI.