Wage Discrimination?

In the context of an article about wage discrepancy laws, the Lincoln Journal Star recently contained a remark that said something like this: "According to the US Census Bureau, women earn 73 cents for every dollar earned by men doing equivalent jobs." The way the paper presented it, this looks like evidence of wage discrimination, but is it? Here's some reasons it might not be.

1. What is an "equivalent job?" Is being the chef at Grisanti's equivalent to being the waiter/waitress? It does not seem implausible that men would usually be in the higher up and better paying of two positions when two jobs that are really different are considered equivalent. Is a part time job equivalent to a full time job?

2. Does "equivalent job" mean "equivalent work?" It makes sense to pay women less if they do less work then the men on the same job for reasons of physical capacity. For example, if there are women construction workers, it would be plausible for them to statistically have a lower work output, and thus be paid less.

3. Do women, on average, earn 73 cents for every dollar earned by men on average? Or does American Womankind earn 73 cents for every dollar earned by the declined American male? If there are more working men and the study used the second option, wage discrimination would probably not exist.

4. It is possible (though unlikely) that men create a better "impression," either in their initial interview or in the workplace. I don't think that having a part of the wage be based on impression counts as discrimination.

5. Some employers (such as my grandfather) view women employees as relatively unreliable because they have to occasionally take off time at work to have children or take care of home/child matters. Just as risky mortgage applicants have to pay higher rates, risky employees would have to be paid lower wages.

6. Does the study take into account family-run businesses where a husband and wife work but only the husband counts as the one receiving the money?

7. Last, but not least, the Papal Encyclicals (and probably Chesterton's principles of subsidiarity as well) state that it is ideal if the family lives on one income, the father's and not the mothers, and if possible, companies should pay fathers enough so that mothers do not have to work. An employer with this view (which would not only be Catholic employers) would likely pay his women less. This is not discrimination.