Education expenditures per pupil differ tremendously across school districts in the US. For example, in 2017, Arlington County, Virginia spent about $19,000 per pupil while Prince William County, Virginia spent about $11,000 per pupil. Median household income is $108,706 in Arlington County and $98,546 in Prince William County. After being told these facts, the Secretary of Education argues that the differences in expenditures are socially efficient, because people choose where to live based on their preferences for schooling. Provide an argument for why these differences might not be socially efficient.