Inflation is a persistent increase in the level of consumer prices or a persistent decline in the purchasing power of money, caused by an increase in available currency and credit beyond the proportion of available goods and services. Inflation as one of the social monsters has many disadvantages; it creates uncertainty, in that people do not know what the money they earn today will buy tomorrow, which discourages productive activities, saving and investment. Further, it reduces the competitiveness of the country in international trade. High inflation in extreme cases "hyperinflation" can lead to a breakdown of the economy, in which money loses its value or real purchasing power and people lose confidence in money as the value of savings is reduced. Inflation can get out of control - price increase lead to higher wage demands as people try to maintain their living standards; known as wage-price spiral. Besides, borrowing may also be favoured through the expense of savers as the real value of existing debts erodes when the real interest rates are negative.