Sociologist Douglas Massey offers two solutions to alleviate wage inequality: greater investments in education and elimination of racial segregation. He notes that, in a globalized economy, those with only physical labor to offer suffer. He argues that investments in education, especially higher education, will result in higher rates of economic growth and lower income inequality. By eliminating racial segregation, Massey argues that many divides between races that exist would be broken down, including income segregation. To accomplish the abolition of racial segregation, Massey argues, simple enforcement of legislation already in place, such as the Fair Housing Act, the Home Mortgage Disclosure Act, and the Community Reinvestment Act, is required. For more group-specific policies, focus on education and language inequalities could be helpful in equalizing employment opportunities, but other more specific policies are dependent on further research on wage gaps for various groups. To tackle wage inequality specifically in companies, random job audits at the national, state, and local levels have been suggested. Audits have been used to study and find wage inequality in the past and could be used as way to actively monitor the presence of the racial wage gap in companies. Evaluating and understanding the causes and consequences of the racial wage gap for various races is an important part of understanding racial inequality in the United States; however, the wage gap does not encompass all aspects of inequality and therefore is useful when understood in conjunction with other types of inequalities. For example, sociologists Mary C. Waters and Karl Eschbach note that other types of inequalities are important for a holistic understanding of inequality in the United States, "including health and demographic measures, such as infant mortality rates, life expectancy, morbidity, and disability. Ethnic and racial groups also differ in rates of homeownership, residential segregation, overall wealth, exposure to crime and toxic pollutants, and in access to power in the upper reaches of our society". Thus, the racial wage gap is just one aspect of inequality in the United States. A criticism of the racial wage gap has been noted by a few scholars: the racial wage gap fails to account for the number of people of a specific race that are unemployed. Examining median incomes does not reflect the growing racial disparity in joblessness. The Butler-Heckman hypothesis states that the least-skilled members of society are also the ones who are most likely to be not working, suggesting that the wage gap does not account for the overall difference in wages between races. An analysis of the black-white wage gap which accounted for unemployment found that when unemployment was included in the calculation of the weekly wages convergence from 1950 to 2000, the convergence percentage went from 13 percent to only 3 percent.