The Threshold Effect of Government Investment and Public Debt on Economic Growth in Oil Exporting Countries: A Panel Smooth Transition Regression (PSTR)Approach

Government investment and public debt are two important tools of financial policy affecting macroeconomic performance, which can be considered as one of the few remaining policy instruments to support growth. In the current study, the panel smooth transition regression model (PSTR) has been used to identify the threshold levels of government investment and public debt in 23 oil exporting countries during 2000 to 2021. Considering investment and public debt in separate models as transmission variables, the estimated results indicate the existence of a two-regime non-linear relationship. The estimation results show that in this group of countries, the positive effects of government investment on economic growth increase with the increase in the level of investment. During the first regime, public debt has a negative effect on economic growth. If public debt surpasses the threshold level, its negative impact on economic growth decreases.