Minnesota's attempt to equalize school spending through state payments to low-expenditure districts succeeded only partially in reducing statewide variation in districts' per-pupil expenditures. To test the effects of the state's 1973 law, and to test a new statistical technique for simultaneous assessment of variability in many factors, researchers gathered data on size in 1973, wealth in 1970, per-pupil expenditures in 1973 and 1979, and enrollment trends from 1973 to 1979 for each of 432 Minnesota school districts. Variability in expenditures was measured by the size of the standard deviation from the statewide mean. Data analysis using the new technique showed that variation in per-pupil expenditures across all districts fell 13 percent from 1973 to 1979. The largest reduction in variability occurred among small, low-wealth districts, especially those with declining enrollments. The smallest variability reduction took place in large, high-wealth districts. (RW)