A longitudinal study that followed students from fourth grade into adulthood gives empirical proof that good (or bad) teachers do make a difference. Having a good teacher in the fourth grade alone increases by 1.25 percent the likelihood that a student will go to college and decreases the chance by the same amount that a female student as a teenager will get pregnant. Having a very poor teacher is tantamount to a student's missing 40 percent of the school year, an intolerable truancy rate. Nicholas D. Kristof notes that the quality of public school education is hardly getting any notice in the primary campaigns. Improving the quality of education may be the most essential strategy for the nation's economic development and job creation in the future (New York Times, January 11).