Suppose we transfer one person from Mexico to United States (illegally or otherwise). As a result his wages increase compared to what he was making in Mexico. Let us also suppose that as a result of this transfer the wages of some unskilled worker in US fall. Furthermore we will ignore the aggregate gains from immigration that occur and which all economists, including Borjas admit exist. We do this to make our job harder, not easier.
How much do you have to weight the native’s welfare relative to that of the Mexican immigrant in order to oppose moving this migrant into US?
YouNotSneaky assumes that utility is a CES function of the wage and goes from there. It’s an interesting back of the envelope calculation. His result: “Clearly one doesn’t need to be a rootless cosmopolitan to reject these kinds of weights. One only need not be a jerk.”