Asymmetric Effect of Oil Rent on Public Debt in Iran

Considering the significant increase in the public debt burden in Iran over the past years and considering the dependence of the government's budget on revenues from oil sales, this study investigated the short-term and long-term asymmetric effects of oil rent on public debt in Iran during the years 1996-2021. For this purpose, the augmented bounds cointegration test and Non-linear Autoregressive Distributed Lag (NARDL) estimator have been used. The results show that the short-term and long-term effect of the increase in the share of oil rent from GDP on the share of public debt from GDP )public debt burden index) is negative and significant and this effect is positive and significant for the decrease impulses; In such a way that the size of effects of increasing impulses is smaller than the effects of decreasing impulses (confirmation of asymmetric effects). The results of the asymmetric Granger causality test also show the existence of a causal relationship from the increasing impulses of the public debt burden to the increasing impulses of the share of oil rent from GDP, which confirms that high levels of public debt in the country lead to the faster extraction and sale of oil resources. According to other results, economic growth has a negative and significant effect, the share of consumption expenditure in GDP has a positive and significant effect, and inflation has an insignificant effect on the public debt burden in Iran. Based on this, regulating and limiting the level of public borrowing during periods of booming oil revenues, transferring natural resource revenues through the financial system to the real sector, and adopting anti-corruption policies to prevent the deviation and waste of oil revenues in order to have a greater effect of oil rent on public debts and on the other hand, the control of public debts and the correct management of the ratio of debt to GDP in order to reduce the speed of extraction and sale of oil resources are the most important policy recommendations of this research.