اثر نوسانات ارزی بر شاخص قیمتی فرآورده های نفتی در بورس اوراق بهادار تهران با استفاده از مدل MS-VAR (مقاله علمی وزارت علوم)
درجه علمی: نشریه علمی (وزارت علوم)
آرشیو
چکیده
با توجه به نوسانات ارزی رخ داده در اقتصاد ایران، بازار سرمایه دستخوش تغییرات چشمگیری شده است. گروه فرآورده های نفتی در مقایسه با صنایعی که ارزآوری بالایی دارند، بیشترین سهم را در شاخص قیمت بازار سرمایه به خود اختصاص داده است. پژوهش موجود تلاش می کند اثر نوسانات نرخ ارز را بر شاخص سهام فراورده های نفتی در بورس اوراق بهادار تهران با استفاده از داده های ماهانه دوره 1398:12-1387:10 و با بهره گیری از رویکرد غیرخطی مارکوف سوئیچینگ بررسی کند. در این پژوهش از قیمت دلار در بازار آزاد به عنوان متغیر نرخ ارز و از شاخص قیمت فرآورده های نفتی در بورس اوراق بهادار تهران به عنوان یکی از صنایع مهم ارزآور موجود در بازار سرمایه استفاده شد. از میان حالت های مختلف الگوی مارکوف سوئیچینگ، الگوی MSIAH(2) - VAR(2 ) انتخاب شد. یافته های تجربی تحقیق نشان می دهد که تنها در رژیم 1 (رژیم با نوسانات بالا)، نرخ ارز رابطه علّی شاخص سهام فرآورده های نفتی است و افزایش نرخ ارز باعث افزایش شاخص سهام فرآورده های نفتی شده است؛ درحالی که شاخص سهام فرآورده های نفتی اثری بر نرخ ارز ندارد. علاوه بر این، نتایج نشان می دهد احتمال پایداری رژیم 2 (رژیم با نوسانات کم) بیش تر است.The Effect of Exchange Fluctuations on the Petroleum Products Stock Index by using MS-VAR
1- INTRODUCTION
Because of the exchange fluctuations in Iranian economy, the capital market has undergone significant changes. the petroleum products stock index has the largest share in the capital market price index compared to currency industries. the present study tries to investigate the impact of the exchange rate crisis on the petroleum products stock index in Tehran stock exchange by using the monthly data of the period of 2009:1-2020:3 and using the nonlinear Markov switching approach.
2- THEORETICAL FRAMEWORK
Due to the high dependence of foreign exchange reserves on the oil foreign exchange receipts (DEXO) and the sharp decline in these receipts, the central bank has faced limitations in supplying the foreign exchange to the market. thus, reducing the currency resources and supplying the foreign exchange on the one hand, and the growth of the foreign exchange demand on the other hand, have caused the raise in the exchange rate.
Economic sanctions have always affected the foreign exchange market, the extent of which depends on the severity of the sanctions. the most important reason for the volatile increase in the exchange rate in recent years is the oil and banking sanctions against our country. economic sanctions will significantly reduce the oil and non-oil exports by restricting the purchasing of the trading partners, and through the channel of declining the foreign exchange earnings will lead to a decrease in the supply of the foreign exchange, and consequently a sharp increase in the exchange rate (devaluation of the national currency). now, we turn to the mechanism of transferring the currency crisis to the stock prices.
Changes in the exchange rates can have two different impacts on the stock prices. on the one hand, the increase in the exchange rate (in terms of demand) has led to an increase in the income of the exporting companies (such as refineries, petrochemicals, metals, mining, etc.) and, consequently, their stock prices, and on the other hand (based on the supply), leads to lower profits for the importing companies such as some automotive, pharmaceutical and food industries, as well as the transportation and leads to lower stock prices.
In addition to dividends, stock buyers also pay attention to the changes in the company's intrinsic value. the intrinsic value of industries whose creation and operation require the supply of machinery from abroad, is affected by the exchange rate changes. and if a company imports the machinery at lower exchange rates, the intrinsic value of the company will increase as the exchange rate increases, and this intrinsic increase intensifies when the establishment of a similar company is not possible due to the high exchange rate, and if the company's products are produced exclusively, its demand will increase and the company's profit will be higher over time. on the other hand, the share of depreciation cost of machinery in the cost of goods produced by the company decreases. considering the above cases by investors, the demand for the shares of these companies will increase and this will increase the stock prices of these companies. in addition, if the exchange rate decreases over time, it will cause the opposite effect for these companies.
3- METHODOLOGY
Recently, the use of the nonlinear models in fluctuation studies has expanded because of this assumption that the linearity of the exchange fluctuations is a large and unrealistic limitation for these studies. this pattern is also known as the pattern of the regime change. the regime change means that a policy variable may show a behavior in one period of time and behave differently in another time period. therefore, if this issue is not considered in the study of the behavior of the variable, the biased results will be obtained. markov rotation models, as the nonlinear models, are able to model the behavioral pattern of the changing status of the dependent variable over time. in nonlinear models, it is assumed that the behavior of the variable on which the modeling is performed is differently and changes in different states.
For this purpose, among the various modes of Markov switching model, MSIAH (2) –VAR (2) has been selected.
4- RESULTS & DISCUSSION
The empirical findings of the study show that only in a regime with high fluctuations (first regime), the exchange rate is the causal relationship of the petroleum products stock index and the increase in the exchange rate has increased the petroleum products stock index, while the petroleum products stock index has no impact on the exchange rate. In addition, the results indicate that the sustainability of the petroleum products stock index in the regime with the low fluctuations (second regime) was more than of the regime with the high fluctuations (first regime).
5- CONCLUSIONS & SUGGESTIONS
Due to the results of the present study, there is a one-way relationship between high exchange rate fluctuations and the stock index of petroleum products. investors active in the stock market, in addition to considering how the stock index of petroleum products is affected by other influential domestic variables, should also consider high exchange rate fluctuations and make their decisions. it is suggested that shareholders, in order to benefit from the growth of the capital market index, as soon as the exchange rate rises sharply, buy shares of companies exporting goods, such as refineries, petrochemicals, metals, mining, etc. also, as soon as the exchange rate falls sharply, sell the shares of the mentioned companies and buy the shares of companies independent of the exchange rate in order not to suffer from the risk of a decrease in the stock index.
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