When the idea of social trends revived in the US in the 1960s it was, to begin with, motivated by concerns almost as unfocused as before. This time, however, the idea caught on, and it has evolved into many lines of inquiry. The setting was more appropriate for systematic social measurement than before, and the movement has developed a momentum which it is unlikely to lose. Some nations have already begun regular production of compilations of social indicators and international organizations are pressing forward with projects which will produce increasing social statistics in developing countries. For those who demand immediate results from social indicators it is worthwhile to note that economic indicators began in the 1920s. Some specific indicators existed before then, like price indices and employment measures, but in the twenties the National Bureau of Economic Research amassed hundreds of economic measures, and followed them over time.