Has the average annual interest rate paid to the Social Security Trust Fund over its lifetime exceeded the average annual inflation rate?
From the outset of Social Security in 1937 through 2018, the U.S. government paid an average annual interest rate of 5.2% on the debt that it owed to Social Security. During this period, the average annual inflation rate, as measured by the Consumer Price Index, was 3.6%. The interest rates on the Social Security Trust Fund are driven by the same factors that affect the interest rates on other government debt. These include but are not limited to inflation, economic growth, Federal Reserve policies, and investors' assessments of risks and rewards. By law, any Social Security surpluses must be loaned to the federal government, which is a requirement that was established in the original Social Security Act of 1935. The federal government is legally required to pay back this money with interest, it has done so every year since 2010.