Has the socioeconomic achievement gap narrowed over the past 50 years?
Core argument: The socioeconomic achievement gap between top and bottom deciles stands at about 1.0 standard deviations, equivalent to four years of learning, and has not changed significantly over the past 50 years.
The socioeconomic achievement gap remains strikingly persistent, with disparities of about 1.0 standard deviations between the top and bottom deciles and around 0.8 standard deviations between the top and bottom quartiles. These gaps, equivalent to four years of learning, have not significantly changed over the past 50 years. While average student performance has improved by 0.5 standard deviations at age 14, these gains vanish by age 17, indicating no rising tide as students transition to college and careers. For the 1954 birth cohort, the achievement gap was slightly less than 1.2 standard deviations, decreasing marginally to about 1.05 for those born in 2001. The 75-25 gap also shows minimal reduction, settling just below 0.8 standard deviations for the 2001 cohort. Despite some early narrowing in math achievement, recent decades have seen a return to previous levels, while reading gaps remain flat throughout the period.






Ed Comment:Survey of charter school studies on selection biases including Kipp school that tried to take over a public school (ie without selection) and failed.