on by employers, could perpetuate over time to other employers in which occupational inequality could decrease nationally. Other theories and research suggests occupational inequality is increasing and will continue to do so. According to the process of "aging effects", occupational inequality will continue with advancing age. According to this theory, the labor market consists of two sectors of jobs; one is the "primary" core of good jobs with good working conditions, advancement opportunities and job safety. The other is the "peripheral" sector of bad jobs with bad working conditions, low advancement opportunities and little job safety. Mobility between these two groups is very difficult. Women and minorities are disproportionately placed into the peripheral sector early on in their careers with little chance of moving into the primary group to achieve equal occupational status. The theory of "homosocial reproduction" points to a trend where those in high position tend to pick the employees who have similar social backgrounds as their own for advancement. Since the majority of managers are men, women are less chosen for career advancement and thus occupational inequality increases. Measurement The Duncan Socioeconomic Index (SEI) has been most commonly used to measure Occupational Status. It is based on two factors, occupational earnings and occupational education. One way occupational inequality is measured is by the index of dissimilarity (D). The equation is as follows: D=½εi|Xi-Yi| where Xi equals the percent of race or sex group X in the labor force in occupation i and Yi equals the percent of race or sex group Y in occupation i. D is the measure of one half the sum of the absolute difference between the percentage distributions. The values range from 0 to 100 and measures the relative separation or integration of groups across an area. If the value equals 0% it means the area is distributed evenly. If the value is 100% it means the area is completely segregated. If the value is 60%, for example, it means 60% of workers would have to change occupations to make the distributions equal. Occupational segregation Occupational inequality is often linked with occupational segregation in a work place. The greater the segregation in a workplace, the greater the occupational inequality. This is true specifically for jobs dominated by a certain minority or women. They often have bad work environments and less income than white males who usually make up the managerial positions with better