Alan Krueger, Assistant Secretary of the Treasury for Economic Affairs, suggested in a recent speech a useful metaphor to distinguish different kinds of economic indicators. Some indicators are like the gauges on the dashboard of the car — industrial production, unemployment, inflation and so on. They give the latest bits of information on the business cycle outlook, for businesspeople, government policy-makers, economic forecasters, and anyone else who wishes to follow such developments at high frequency. Many of these numbers are collected on a monthly basis. Other statistics are like the results of 10,000 mile checkups – the poverty rate, infant mortality, life expectancy, carbon emissions, natural resource depletion, the crime rate, traffic congestion, leisure time, and other measures of inequality, health, the environment and the quality of life. They supplement market-measured activity and are needed in order to get a comprehensive feel for welfare and the longer term sustainability of the economy. This second category of statistics is more often collected on an annual basis.