prestige as a weighted average of income and education and this is the operational definition used in indices like DSI and ISEI. However other people (especially in the working class) seem to have more moralized notions of how much a job helps society and would, for instance, rate doctors high and lawyers low even though both jobs require postgraduate degrees and earn high incomes. The indicators most commonly used to measure SES come from Duncan's (1961) Socioeconomic Index (SEI), a composite of occupational prestige, income, and education. Duncan used data from North and Hart's study of 1949 occupational prestige and census data to conduct the first correlational study of the statistical relationship between education, income, and occupation. Duncan focused on white males with at least a high school education and income of $3,500 dollars or more in 1949, and found correlations among income, public-ranking of occupational prestige, and educational level of around 0.75. The study did not report whether the index included a sample of ethnic minorities. The SEI model continues to influence the way researchers measure SES. The National Educational Longitudinal Study (NELS:88, NCES, 1988) initially employed a measure of SES developed by Stevens and Featherman (1981) based on father's income, mother's income, father's education, mother's education, and father's and mother's occupation as rated by the SEI model. In the first-year follow-up study, the National Center for Education Statistics (1990) used the Nakao and Treas (1994) revised SEI model. Calculating occupational prestige in the United States During the 1960s through the 1980s job prestige was calculated in a variety of different ways. People were given index cards with about 100 or so jobs listed on them and had to rank them from most to least prestigious. This ranking system was known as placing jobs in a "ladder of social standing." Another method they used in this time period was to have the respondents rank jobs on a "horizontal ruler" using specific guidelines such as estimated income, freedom of choice, and how interesting the job was. No matter what the method the outcomes were generally the same. Although pay and fame have little to do with occupational prestige, measures of prestige are a part of the concept of socioeconomic status (SES). Jobs with high prestige are more likely to have a higher level of pay stability, better lateral career mobility, and established professional associations. Some popular scales that are used