While an increase in the purchasing power of one's money benefits some, it amplifies the sting of debt for others: after a period of deflation, the payments to service a debt represent a larger amount of purchasing power than they did when the debt was first incurred. Consequently, deflation can be thought of as an effective increase in a loan's interest rate. If, as during the Great Depression in the United States, deflation averages 10% per year, even an interest-free loan is unattractive as it must be repaid with money worth 10% more each year.