Pre- and Post-Mating Decisions;Trophy Spouses?

From Mahalanobis:

Married men earn more than bachelors so long as their wives stay at home doing the housework, according to a report Wednesday from Britain's Institute for Social and Economic Research (ISER).

There are many competing hypotheses here.
1) Specialization leads to greater efficiency, so in that case the man can be a better worker.
2) Stay-at-home wives may prefer men with more earnings power, so it is really the women choosing the higher income men as opposed to creating them.
3) Men may prefer stay-at-home wives, but these are costly to support. Here men's preferences are creating the disparity, in that wealthy men disproportionately can afford to choose women with stay-at-home preferences.

I'd venture that married women also earn more than comparable single women if their husbands do all the homemaking chores. If so, how common is it for these guys to be perceived as trophies? If rarely, then the specialization hypothesis takes on more credibility.

Here's a further hypothesis for testing: married women earn less than their single counterparts if they are expected to manage the bulk of the homemaking chores in addition to a full-time job. The same specialization explanation applies, only with a variation. Assuming homemaking is more time-consuming for a family than for a single woman, a married woman will have more demands on her time unless her partner takes on a big chunk of the homemaking tasks, which, I gather, doesn't really happen all that much. This hypothesis helps explain the Fraser Institute result of many years ago that never-married women have incomes that are similar to those of comparable men.