Healthy price increases are essential for sustainable economic development. Economists believe that sustained inflation occurs when the money supply (that is, money in the hands of the population and in banks) grows slightly faster than the economy as a whole. The optimal level of inflation is necessary in order to to a certain extent stimulate the population's expenditures, and not savings, thereby contributing to economic growth. That is why the world's central banks control inflation: they set a target level of stable low inflation and try to maintain it. With such a moderate annual rise in prices, industry will develop, and people will willingly spend part of their earnings, without worrying about income and savings.