چكيده لاتين
Along with the widespread spread of the corona virus all over the world in the past years, various aspects of human life were directly affected. This epidemic not only endangered the lives of millions of people, but due to it, the economic conditions of the countries also underwent many changes. In the period of increasing number of infected people in the world, countries were trying to reduce the infection rate and then the death rate. Therefore, they adopted different policies including quarantine. On the other hand, the quarantine caused a decline in the activity of many businesses and ultimately reduced the gross domestic income for the countries. The presence of this virus caused the institutions and companies to face many problems in dealing with their imported, exported and manufactured goods, and this caused them to face the challenge of lack of liquidity. According to Keynes, in conditions of widespread uncertainty, a person can keep a part of his savings as precautionary savings. Therefore, more uncertainty means more demand for money, which means a higher interest rate, and as a result, in this situation, with an increase in the interest rate, the amount of investment will decrease and the desire to keep cash will increase. On the other hand, due to the external shocks that Iran has suffered during the past decades, increasing liquidity has been one of the old policies of the central bank to eliminate the effects of these shocks and ultimately economic growth. The purpose of this research is to analyze a demand function that can measure the changes and the type of effect of this virus and finally the effects of this sudden shock on the economy. In this research, by collecting data related to economic changes at the macro level, during the period of 1390 to 1400 and using modeling using the Makoff switching method, we sought to find an answer to interpret the results of the effects of a global epidemic, such as Corona, on It is macroeconomics. In the continuation of this research, it was concluded that the arrival of an external impulse such as an epidemic caused by the spread of Covid-19 increases the precautionary demand for money storage and ultimately increases liquidity
