answer: menu cost refers to the cost that enterprises need to provide new price lists to salespeople and customers in order to change the prices of goods they sell. It is an important reason for neo-Keynesianism to counter the criticism of neoclassicism and prove the price rigidity it advocates. Economists have different views on whether menu cost can cause short-term price rigidity. Some economists believe that the menu cost is usually very small and it is impossible to have a huge impact on the economy. Another part of economists think that although the menu cost is very small, due to the externality of total demand, the nominal price will be rigid, which will have a great impact on the whole economy and even cause periodic fluctuations.