Multivariate linear regression: how to test for whether the slopes are the same?
Estimate the model 
$$W_i=a_1+a_2E_i+a_3G_i+a_4E_iG_i+\epsilon_i,$$
where $W,E,G$ denote wage, education, and an indicator for gender (e.g. 1 if male, 0 if female), respectively. The term $EG$ is an interaction term obtained by multiplying the gender dummy by education. A simple t-test of the hypothesis $H_0: a_4=0$ will tell you if the effects of additional education on wage are significantly different for different genders.