Occupational structure and growing wage inequality in the U.S., 1983 - 2002

textSince the 1980's, wage inequality in the U.S. has been dramatically increasing. I investigate the impact of occupational structure, measured at the three-digit level, on this trend of growing wage inequality. The investigation is conducted in terms of three major research tasks. First, I test the validity of the 'disaggregate structuration' view in relation to growing wage inequality. The 'disaggregate structuration' view is suggested as an alternative to big class theories. Theorists of the 'disaggregate structuration' view assert that an occupation is a gemeinschaftlich community characterized by internal homogeneity. Thus, this view implies that most of the rise in inequality occurs between occupations and that within-occupational inequality is actually decreasing, due to the progress of 'occupationalization.' My analyses, however, find that the majority of the growth in inequality has occurred within occupations. Secondly, I thus seek a more delineated explanation for the causes of rising within-occupational inequality. I investigate whether previously proposed hypotheses can account for this phenomenon. Hypotheses that I test include demographic change, deindustrialization, unions, insecure employment relations, increases in the return to skill, and changes of firm organizations. Although smaller than within-occupational inequality, between-occupational inequality has also been growing during this period. Thirdly, I therefore investigate the changes of between-occupational inequality. Since between- occupational inequality is a weighted sum of occupational mean wages, I examine whether the same hypotheses tested for within-occupational inequality can explain the changes in occupational mean wages over time. Using the Current Population Survey (CPS) from 1983 to 2002, I find that as within-occupational inequality has grown faster than between-occupational inequality, the direct association between occupational structure and wage inequality has declined over this period. While the importance of general skills (i.e., education) in determining workers' wages is growing, the importance of occupation-specific skills is declining. For regression models of hourly wages, the amount of R-squared increase by adding three-digit occupational codes (331 occupational dummies) in addition to general skills (5 dummies of education) has decreased for this period. Therefore, the strong version of 'aggregate structuration' and 'occupationalization' is not supported. I would like to note, however, that the R-squared of hourly wage increases jumped significantly when we use three-digit occupational codes instead of one-digit occupational codes even after adjusting for the degrees of freedom. Thus, the weak version of structuration is not rejected. For multivariate tests, inequality indexes and other variables by detailed occupation are extracted from each year's CPS and merged into one panel data file with occupation as a unit of analysis. Multi-level growth models are then estimated using detailed occupational categories as the unit of analysis in order to assess how the structural characteristics of occupations affect changes in mean wages and wage inequality over this time period. Contrary to the expectations of the skill-biased technological change hypothesis, changes in the distribution of education do not affect the growth of wage inequality within occupations. In contrast to the traditional view of unions as promoting wage equality, within-occupational inequality is increased by unionization. The increase of female labor market participation seems to pull down inequality in an occupation. Deindustrialization does not account for the rise of intra-occupational inequality, while insecure employment relations do. As expected by the organizational change view, inequality grows faster in high skill jobs and service jobs. Regarding between-occupational inequality, traditional explanations do better jobs in accounting for its change than for within-occupational inequality. Skill biased technological changes and unions have positive effects on occupational mean wages. Multi-level growth models provide additional evidence against disaggregate structuration. The disaggregate structuration view assumes that occupational common interests will be achieved as accomplishment of active occupational associations. Thus, the changes of occupational mean wage, which is a clearly common interest of members in an occupation, should be explained by occupation itself, not by other demographic and institutional variables. Contrary to this expectation, most of the within-occupational variation are not explained well by other demographic and institutional variables, including race, gender, and unions. In conclusion, although sociologists often view occupation as the back-bone of the stratification system, the rise in within-occupational inequality suggests that broader, more complex approaches may be needed in order to better explain the increasing disparity in wages. I suggest that more attention should be given to firm level studies in which changes inside and between firms are investigated.Sociolog

Is hyper-selectivity a root of Asian American children's success?

Asian immigrants' children, even those from lower-backgrounds, tend to acquire higher levels of education than other ethnoracial groups, including White natives. Asian culture is often cited as a conventional explanation. The hyper-selectivity hypothesis challenges conventional wisdom by arguing that Asian American culture is an outcome of the community resources associated with hyper-selectivity. In this study, we assess the validity of the hyper-selectivity theory by examining the association between the magnitude of hyper-selectivity measured by the proportion of the BA + degree holders among the 1st generation Asian immigrants across communities and the likelihood of school enrollment for 1.5 and 2nd + generation Asian American children. Our results cast doubt on the hyper-selectivity theory. Asian American children's school enrollment is associated with the magnitude of educational selectivity among Asian immigrants for neither high school nor college. The benefits of hyper-selectivity do not seem to be cross-class or cross Asian ethnic groups. The higher the hyper-selectivity in a community is, the larger the education gap between upper- and lower-background Asian American children. The implications of these findings are discussed

Is Rising Earnings Inequality Associated with Increased Exploitation? Evidence for U.S. Manufacturing Industries, 1971–1996

This is the published version. Copyright 2010 University of California Press.Is the trend towards rising earnings inequality associated with increased exploitation? The authors investigate exploitation among workers using data for manufacturing industries. Defined as the underpayment of earnings relative to productivity as evaluated in the market, exploitation is measured for various groups of employees. The results indicate significant levels of exploitation among women, Hispanics, African Americans, and blue-collar workers. By contrast, employees who are overpaid relative to their productivities include middle-aged workers, older workers, and managers. Additional findings suggest that the increase in inequality in recent years has been associated with heightened exploitation due to the underpayment of workers in the lowest two quintiles of the earnings distribution, while workers in the upper two quintiles have become increasingly overpaid. Rising earnings inequality in the manufacturing sector thus appears to be associated with increased exploitation when the latter is measured as the underpayment of market value to workers. A related analysis by Liu, Sakamoto, and Su also investigates patterns of economic underpayment and overpayment but does not link them explicitly to inequality in the distribution of earnings and how the level of inequality has been increasing in recent years

Male immigrants with darker skin have fewer job opportunities than women and those with lighter skin.

America’s demographics are changing; by 2065 one in three may be an immigrant. What to these changing demographics mean for American society? In new research Andrea Gómez Cervantes and ChangHwan Kim look at the effects of immigrants’ skin color on their employment opportunities. They find that for male immigrants, darker skin has a negative effect on employment, but found no effect for women. They suggest that assimilation of immigrants into the US has become segmented by gender, race, and skin color

Piecewise exact solution of nonlinear momentum conservation equation with unconditional stability for time increment

Exact solution is adopted for computation of the inviscid Burgers equation on finite difference grid. Initial condition and following computed values of the independent variable are assumed to be piecewisely linear between fixed grid points, and local exact solution is used to find the value at the next time step at each grid point. Comparisons of Piecewise Exact Solution Method (PESM), existing upwind scheme, and the analytic solution show that the present method is more accurate than the upwind scheme. The unconditional stability is a strong merit of this method and is shown with a test result

Mechanical behavior of seismic isolation bearings in earthquake-induced ultimate limit state

High-damping rubber bearings, lead rubber bearings, and natural rubber bearings are often used to improve the seismic capacity of seismic isolation bearings. We present the results of an extensive series of experimental tests to identify the mechanical characteristics of these three types of seismic isolation bearings. Cyclic horizontal displacement tests, varying the test parameters of shear displacement amplitude axial load, and loading frequency tests were performed on each type of bearing. Bearing shear stiffness and damping properties were investigated in terms of the different test parameters. The ultimate tests consisted of monotonic shear loading to failure under axial loads, and tension failure tests of the bearings with bolted connections. Comparisons are made between experimental results and available analytical relationships for material and bearing properties

Field of Study in College and Lifetime Earnings in the United States

Our understanding about the relationship between education and lifetime earnings often neglects differences by field of study. Utilizing data that matches respondents in the Survey of Income and Program Participation to their longitudinal earnings records based on administrative tax information, we investigate the trajectories of annual earnings following the same individuals over 20 years and then estimate the long-term effects of field of study on earnings for U.S. men and women. Our results provide new evidence revealing large lifetime earnings gaps across field of study. We show important differences in individuals’ earnings trajectories across the different stages of the work-life by field of study. In addition, the gaps in 40-year (i.e., ages 20 to 59) median lifetime earnings among college graduates by field of study are larger, in many instances, than the median gap between high school graduates and college graduates overall. Significant variation is also found among graduate degree holders. Our results uncover important similarities and differences between men and women with regard to the long-term earnings differentials associated with field of study. In general, these findings underscore field of study as a critical dimension of horizontal stratification in educational attainment. Other implications of the empirical findings are also discussed

Education and Lifetime Earnings in the United States

Differences in lifetime earnings by educational attainment have been of great research and policy interest. Although a large literature examines earnings differences by educational attainment, research on lifetime earnings—which refers to total accumulated earnings from entry into the labor market until retirement—remains limited because of the paucity of adequate data. Using data that match respondents in the Survey of Income and Program Participation to their longitudinal tax earnings as recorded by the Social Security Administration, we estimate the 50-year work career effects of education on lifetime earnings for men and women. By overcoming the purely synthetic cohort approach, our results provide a more realistic appraisal of actual patterns of lifetime earnings. Detailed estimates are provided for gross lifetime earnings by education; net lifetime earnings after controlling for covariates associated with the probability of obtaining a bachelor’s degree; and the net present 50-year lifetime value of education at age 20. In addition, we provide estimates that include individuals with zero earnings and disability. We also assess the adequacy of the purely synthetic cohort approach, which uses age differences in earnings observed in cross-sectional surveys to approximate lifetime earnings. Overall, our results confirm the persistent positive effects of higher education on earnings over different stages of the work career and over a lifetime, but also reveal notably smaller net effects on lifetime earnings compared with previously reported estimates. We discuss the implications of these and other findings

An improved Bayesian inference model for auto healing of concrete specimen due to a cyclic freeze-thaw experiment

This paper presents an innovative solution for the auto healing porous structures damaged by cyclic freeze-thaw, followed by predicting the results of recovered damage due to freezing based on Bayesian inference. The additional hydration of high strength material, cured in high temperature, is applied as auto curing for the damaged micro-pore structures. Modeling of micro pore structure is prior to damage analysis. The amount of ice volume with temperature dependent surface tensions, freezing pressure and resulting deformations, and cycle and temperature dependent pore volume has been predicted and compared with available test results. By heating the selected area of specimen in frozen chamber, approximately 100 % of strength recovery has been observed after 10 days of freeze-thaw tests in the proposed nonlinear stochastic prediction models and the experimental results