Another policy to reduce the gender pay gap could be to improve the education and training of women. In a free labour market, wages are determined by supply and demand of labour alone. So, if the demand for female workers is lower than the demand of male workers, then the best policies would focus on improving this. Demand for labour at any given wage is determined by three main factors, which are demand for the good itself (as labour is a derived demand), substitutability of capital, and productivity of workers. The main difference between two groups of workers would be their productivity, which would be affect marginal revenue product. This is how much extra revenue each unit of labour contributes to a firm. If women had better education and training, they would have a similar or higher MRP compared to men. Then firms would increase their demand for female workers. The diagram below shows this.
Wages go up from W1 to W2 and quantity of female workers employed go up from Q to Q2 due to an increase in education and training causing an improvement in MRP causing greater demand for female workers.
However, improving education and training has a high opportunity cost as well, and also a large time lag. If the government introduced better training schemes, it would take a few years for people to enrol and benefit from higher wages. It is also not guaranteed if firms would respect the training schemes and increase pay, as they could have the perception that MRP has remained low. Overall, better education and training schemes are arguably worth introducing as they are more of a permanent solution to the gender pay gap issue rather than a quick fix (minimum wage).