I think the ambiguity is between productivity as a result of feeling compelled to work, versus productivity as a result of being more competent. I think people

I think the ambiguity is between productivity as a result of feeling compelled to work, versus productivity as a result of being more competent. I think people confound competency into the so-called "marriage penalty" and think along the lines of "more competent workers are more suitable mates and therefore more likely to be married". But I think it's more likely the increased productivity (if there is any, as there are clearly countervailing forces) is a result of being compelled to work harder because there's a family to support. So it's not at all clear to me that there's some positive signal to employers from being married. Certainly in the end the married guys get paid a lot more though!