A common thread in inequality research is to examine social status or position as either an outcome or a predictor variable. One example might be how research on discrimination in employment focuses on sex or race differences in wages, job quality, mobility chances or status outcomes. Measurement error normally attenuates the effects of variables. For example, there is evidence which suggests that the role of key status attainment variables, like education, may be attenuated significantly due to measurement error. Drawing on data from the Household, Income and Labour Dynamics in Australia Survey and the British Household Panel Survey, our research addresses the extent to which the reliability of core employment measures changes over time and across sub-groups of panel samples, such as sex, age and education. Employing quasi-simplex models to obtain relibality estimates, we focus on core measures of respondent wages and hours. We conclude with a discussion of how reliability assessments of variables like these may affect substantive research, most notably examinations of discrimination in employment and wages.