Investigating how the rural population growth rate of Iran's provinces is influenced by economic shocks

Introduction
Some countries are facing the challenge of decreasing population growth and to increase the population growth rate of their country, they have implemented policies to support its increase. One of the reasons for the decrease in the population growth rate is the economic factors and the resulting instabilities. Economic cycles and the resulting fluctuations affect the demographic structures of countries and change the demographic dynamics. In general, the mechanisms through which economic factors may affect the population include: the effects of economic uncertainty (Hofmann and Hohmeyer, 2013), job instability and labor turnover (Modena et al., 2014), unemployment of native and immigrant population (Tragaki and Bagavos, 2014; Cazzola et al., 2016), changes in the housing and mortgage market (Schneider, 2015), increased mortality (Lusardi et al. 2015; Stuckler et al. 2015), labor market (Gil Alonso et al., 2016) and factors that indirectly affect fertility, for example delaying marriage (Goldstein et al., 2013) or reducing the marriage rate (Kreyenfeld et al. 2012; Lee and Painter 2013). Since the country of Iran has suffered extensive sanctions many times in the last few decades, on the one hand, the sale of oil and as a result, the government's sources of income have been limited, and on the other hand, macroeconomic variables have experienced severe fluctuations that have faced serious challenges to the country's economy and affected the country's population growth rate. Despite the high importance of this issue, not many studies have been conducted in this field, and the limited studies that have addressed this issue have examined the population growth rate in a country, and no study has investigated the effects of economic shocks on the growth rate of the rural population in the country's provinces. Therefore, it is necessary to examine the effects of economic shocks in order to control the resulting damages.
Materials and Methods
The purpose of this research is to investigate the effects of economic shocks on the growth rate of the rural population of Iran's provinces(Due to the limitation of information for Alborz province, this province was considered together with Tehran province). For this purpose, the Bayesian Panel VAR model was used in MATLAB software during the period of 1997-2022 to investigate the effects of economic shocks.
Results and Discussion
Among the investigated variables, the variables of household income and economic growth are stationary at the level, and other variables become stationary with one-time differentiation. Also, based on Pedroni's test and Kao's test, the existence of a long-term relationship between these variables was proved. The research results showed that the inflation rate, exchange rate and Gini coefficient have a negative effect on the growth rate of the rural population of the provinces. The effect of the shock of economic growth and household income in the short term for most provinces on the growth rate of the rural population has been positive, but with the passage of time and in the long term due to the increase in migration from the village to the city, its effect becomes negative and leads to a decrease in the growth rate of this variable. Also, The results were significant for all provinces. In addition, the results of variance decomposition showed that after 20 periods for all provinces, the inflation rate had the greatest impact on the rural population growth rate(with the exception of the self-variable effect) and the Gini coefficient had the least impact on this variable in most provinces. In addition, the highest and lowest effects of variance decomposition on the growth rate of the rural population from the variable itself are for the provinces of Yazd (96.84%) and West Azerbaijan (59.06%), respectively. Also, for the variables of inflation, economic growth, Gini coefficient, government expenditures and exchange rate, the greatest effects of variance decomposition on the growth rate of rural population are for the provinces of West Azarbaijan, Tehran, Khorasan Razavi, Mazandaran and West Azarbaijan, respectively, and the least effect in all variables is for the province of Yazd.
Conclusions
As the results of the research showed, one of the main factors affecting the growth rate of the rural population are economic factors. Considering the limited income of the country and the existence of international sanctions that have limited the government's access to strong currencies such as the dollar and euro and have led to economic shocks, It is necessary to follow constructive diplomacy in order to control the fluctuations of economic variables and the shocks caused by them. Another important point about shocks is that an economic shock can cause other shocks. Undoubtedly, the decrease in economic growth has caused a change in the government's income, which, as a result, changes other variables such as imports, inflation, foreign exchange reserves and public expenditures, etc., and and has adverse consequences for the country and the provinces. Therefore, it is necessary to provide conditions so that the country's economy will stabilize and the growth rate of the rural population will suffer less. In addition, the results showed that the Gini coefficient has a negative effect on the growth rate of the rural population. Considering the high importance of the agricultural sector and preventing the migration of villagers to the city, it is necessary for the government to take measures to support the villages.