On the Welfare Cost of Inflation and the Recent Behavior of Money Demand
利用1980年后美国数据发现稳定的长期货币需求关系，估算温和通胀的福利成本很小，表明美联储当前低通胀政策在福利上接近弗里德曼规则。
Post-1980 US data trace out a stable long-run money demand relationship of Cagan's semi-log form between the M1-income ratio and the nominal interest rate, with an interest semielasticity below 2. Integrating under this money demand curve yields estimates of the welfare costs of modest departures from Friedman's zero nominal interest rate rule for the optimum quantity of money that are quite small. The results suggest that the Federal Reserve's current policy, which generates low but still positive rates of inflation, provides an adequate approximation in welfare terms to the alternative of moving all the way to the Friedman rule.