Rates of intergenerational mobility vary widely across the US. This column investigates the effects of reducing differences in revenues and expenditures across school districts within each state on students’ intergenerational income mobility, using school finance reforms passed in 20 US states between 1986 and 2004. Equalisation has a large effect on mobility, especially for low-income students. The effect acts through a reduction in the gap in inputs and in college attendance between low-income and high-income districts.