It ' s almost impossible to accurately determine the exact level of the gender wage gap . When you don ' t include control variables like education and industry we almost certainly get an omitted varibale bias that overestimates the level of the gender wage gap . But if you do include a whole heap of possible explanatory variables , we will also see a selection bias due to the fact that things like education can be bad controls becaue they are also correlated with the outcome variable that is on the LHS of the regression . For example , if their is a wage gap we would expect women to invest less in education , so using education as an explanatory variable will potentialy underestimate the gender wage gap . From my understanding of the literature , no one has found a particularly good instrumental variable that could actually solve this problem . Basically , the gender wage gap in the form of equal pay for equal pay potentially exists but is probably not as high as 77 cents on the dollar . Also , econometrics is hard and I ' m pretty sure all the people saying ' hur dur the wage gap is a myth ' have no idea what they are talking about .