The economic risk and resulting costs of a woman possibly leaving jobs for a period of time or indefinitely to nurse a baby is cited by many to be a reason why women are less common in the higher paying occupations such as CEO positions and upper management. It is much easier for a man to be hired in these higher prestige jobs than to risk losing a female job holder. In a survey conducted of about 500 managers in the Slater &Gordon law firm, more than 40% of the managers agreed they generally hesitate to hire woman who fall in the age group of potentially bearing children or woman who already have children. Thomas Sowell argued in his 1984 book "Civil Rights" that most of pay gap is based on marital status, not a "glass ceiling" discrimination. Earnings for men and women of the same basic description (education, jobs, hours worked, marital status) were essentially equal. That result would not be predicted under explanatory theories of "sexism". However, it can be seen as a symptom of the unequal contributions made by each partner to child raising. Cathy Young cites men's and fathers' rights activists who contend that women do not allow men to take on paternal and domestic responsibilities.