Realized real interest rates, 1920–2015 (qualitative interactive redraw) 20% 15% 10% 5% 0% −5% −10% −15% 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 Year Realized real interest rate (%) Qualitative redraw, not annual data. Shading marks rates below zero: 1940s wartime inflation and the 1980 oil-supply shock. below 0 1946 1946: realized real return is below zero. Unexpected wartime inflation repaid lenders in cheaperdollars — a negative real return they never priced in.