Non-Linear Relationship between Macroeconomic Variables and Government Size in Iran

Attitude towards the role of government and reasons for the existence of government have experienced several changes and revisions during the last century. Attitude changes alter the duties and responsibilities assigned to the government and thus change the size and composition of public expenditure. In the context of these attitudes, there are factors that could explain the changes in the size and the growth of government and consequently the government intervention in the economy over time and among different countries. This study investigates the relationship between government size and macroeconomic variables including economic growth, growth of oil revenues, growth of tax revenues, inflation in Iran using seasonal data during the period of 1990:1 – 2014:4 by applying Markov Regime Switching model. The results show that in the selected model consisting of two regimes with different government sizes, economic growth has a significant negative impact on government size in both regimes of zero and one. But inflation has different effects on government size: it has a negative effect in the regime zero (smaller government) and a positive effect in the regime one (bigger government). Moreover, the growth of oil revenues has a positive effect in both regimes, but the growth of tax revenues has a positive effect only in the regime one. Also, the results indicate that the government size in Iran has often been in the regime one with bigger government size and it is predicted that bigger government will be more sustainable than smaller government.