How many economists does it take to eliminate discrimination against women?

None--the market will do it. If enough employers indulge a taste for discrimination (animus based) against women, this can creates opportunities for rivals to hire women, and make the same goods at lower cost. This seems to be happening in South Korea where US firms are hiring over-qualified, and under-employed Korean women:

Jordan Siegel of Harvard Business School reports that foreign multinationals are recruiting large numbers of educated Korean women...., lifting the proportion of a firm’s managers who are female by ten percentage points raises its return on assets by one percentage point...

In contrast to animus based discrimination, statistical discrimination is profitable.