A summary of their findings is below.
...we found that employed husbands in traditional [wife not employed] and neo-traditional [wife employed part time] marriages, compared to those in modern marriages [wife employed full time], tend to (a) view the presence of women in the workplace unfavorably, (b) perceive that organizations with higher numbers of female employees are operating less smoothly, (c) find organizations with female leaders as relatively unattractive, and (d) deny, more frequently, qualified female employees opportunities for promotion
Study 1 used survey results to measure explicitly sexist attitudes with regards to gender roles (i.e. men should be the breadwinners, women should raise children and keep house).
Study 2 again used survey results, this time to look at perceived organisational smoothness relative to the number of female employees.
Study 3 asked job seekers to evaluate one of two recruitment letters. The letters were identical, except that one had the names of male recruiters, and the statement "INDSCO’s equal employment opportunity programs ensure that all employees can get ahead in our company", while the second had the names of female recruiters, and the statement "INDSCO’s equal employment opportunity programs ensure that all employees can get ahead in our company. For example, representation of women on our board of directors far exceeds the average representation of women in Fortune 500 companies."
Study 4 asked managers to evaluate one of two identical candidates to be sponsored through an MBA program with a promotion to Vice President upon completion of the studies. One candidate had an unambiguously male name, the other a female name.
Across all four studies, marriage structure was statistically significantly indicative of attitudes towards women in the workplace, with men in traditional marriages being more negative than men in modern egalitarian marriages.
Of course correlation is not causation, and the marriage structure itself may be indicative of attitudes held prior to the marriage, for example religious beliefs or an otherwise conservative upbringing. Nor does this mean that men with stay-at-home wives are automatically sexist, either explicitly or implicitly. It does however show (surprise surprise) that personal attitudes do affect professional decisions, specifically decisions made by men that determine career opportunities for women. By gaining a better understanding of the influences on these decisions, organisations can better work towards negating these influences and developing a more egalitarian workplace. Being confronted with this information can also help men who do not wish to be sexist, either implicitly or explicitly, to more accurately consider their own behaviours and attitudes, and how these might be influenced by the work decisions of their wife (or partner).