The business cycles are one of the most important economic indicators that they show the changes in economic activities during time. The study of business cycles is important because the understanding fluctuations in GDP and effective factors on these fluctuations help policy makers to plan better and more efficient. The main purpose of this paper is to investigate the effects of oil price shocks on business cycles dynamics in Iranian economy during period of 2005 to 2017 by using non-linear Markov switching model with the time varying transitional probabilities (MS-TVTP). So, first, the oil price shocks were extracted in four different modes, and then the effect of them on recession and boom regimes are investigated. The results of MS-TVTP model show that business cycles are affected by oil price fluctuations and shocks in Iran’s economy. The results indicate that, in all four modes which oil price shocks were calculated, the positive shocks in oil price increase the probability of staying in boom regime. Also positive oil price shocks increase the probability of transition from the recession regime in Iran’s economy. Also, with relative comparison of the coefficients of oil price shocks in the probability of staying in boom regime and transition from recession to boom regime, it can be argued that positive oil price shocks in recession period increases the probability of transition from recession more than the boom regime. In other words, oil price shocks in recession periods have a greater effect on rotation of economic situation and increase the probability of transition from recession regime, but in the boom regime, the positive oil price shock lead to increases the probability of staying in boom regime a little.
