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Economic liberalization policy has been among the major concern of the governments during the last few decades. However, its impact on economic growth is still a controversial issue. The aim of this paper is to examine the impact of trade liberalization and financial development on economic growth in Iran using annual observations over the period 1973-2007. The current study would use ARDL technique to estimate the empirical model. The findings of this paper indicate that there is a long run positive and significant relationship between trade liberalization and financial development and economic growth in Iran over the period of the study. The error correction coefficient is around 0.32 showing that the adjustment towards the long run equilibrium takes place within almost three years. The Granger causality test indicates that causality runs from trade liberalization and financial development to GDP.

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The assumption of a linear relationship between export and economic growth in previous investigations may lead to invalid inference if the actual relationship is nonlinear. In present study the relationship between export and economic growth in economies of Caspian Sea border countries (Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan) is explored with emphasis on the effect of nonlinearities on the causal relationships. Results of study show that nonlinearities exist in the dynamic relationship between exports and GDP growth. Nonlinear smooth transition autoregressive (STAR) model results suggest that nonlinear Granger causality flows from exports to output growth and vice versa. Predictive accuracy tests further confirm the appropriateness of the nonlinear models over the linear model specification.

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Understanding the nature of the causal relationship among economic variables is crucial for the economic policy-makers and planners. So, this study investigates Granger causality between producer price index (PPI) and consumer price index (CPI) for the economy of Iran. From a policy-making point of view, the findings of the study may inform economic policy-makers in pursuing effective anti-inflationary policies. To this end, monthly data are used over the period 1990- 2011. The results of the cointegration test indicate that there is a long-run equilibrium relationship between these variables. According to Hsiao test, there is bi-directional causality between consumer price index (CPI) and producer price index (PPI) in both short-run and long-run. Toda and Yamamoto test also indicate the bi-directional causal relationship between the variables. However, it seems that causality from PPI to CPI is stronger than that from CPI to PPI, supporting the Cushing and McGarvey (1990) hypothesis.

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For more than a century, the causal relationship between government size and economic growth has been a challenging issue in the public sector economics. However, there is no theoretical or empirical consensus among economists on this issue. Accordingly, it seems that the best way to resolve these theoretical and empirical contradictions is experimentally investigation the causal relationship between government size and economic growth in each country. Therefore, this paper investigates the causal relationship between government size and economic growth using the Markov-Switching Granger Causality Approach in Iran over the period 1967-2017. The findings confirmed the existence of a non-linear causal relationship between government size and economic growth and showed that government size had a significant negative effect on economic growth in the form of a two-regime structure (regime Zero: 1966-2002 and regime one:1983-1987), although this negative effect was greater in regime one than in regime zero. This larger negative effect can be rooted in the fact that the share of current expenditure in total government expenditure was significantly larger in the years related to regime one (compared to regime zero). Finally, contrary to Wagner's law, Findings did not confirm the positive and significant effect of economic growth on government size in Iranian economy.