I know that I’m replying to this comment 4 years after the fact, but I searched for the Lipsey meta-analysis described in the post, and I did not find the same results that Dr. Wolf is describing. According to Table 9 from Lipsey’s report (https://ies.ed.gov/ncser/pubs/20133000/pdf/20133000.pdf), the mean effect size for elementary, middle, and high school interventions were 0.28, 0.33, and 0.23 respectively. The mean effect size varies by the type of test used to measure student outcomes, but even on tests with the lowest effect sizes, the mean effect size for elementary and middle schoolers were 0.8 and 0.15 respectively (high school data was unavailable). If I’m not looking at the correct meta-analysis or I’m looking at the correct meta-analysis incorrectly, feel free to let me know.

]]>I then followed up and sent him 5 reports the Epple survey didn’t cover and pointed out that even Epple, Romano and Urquiola believe vouchers tend to provide benefits when targeted to low-income students and argued that the experiments should be continued and studied.

Smith never responded back. Do you know if “at any horizon” is a special economic term? I’m unfamiliar with it.

At any rate, Smith argued that school choice supporters are ideologues and rational empiricists wouldn’t support such a policy, the opposite of what his own source said. Makes me wonder if I could be a professor at Stony Brook.

I’ll give your report a read now. Thanks.

]]>Mike,

Yes, you are correct. A gain of .2 SD in the older grades is more impressive than a gain of .2 SD in the younger grades. Test scores hardly move at all after 10th grade.

It would take some work but we probably should “grade adjust” our impact estimates as we move forward with the project. Thanks for the suggestion!

]]>Question –

a. is a gain of say, 0.2 in grade 8 more valuable/impressive/worthwhile than a gain of 0.2 in grade 1? ie, my understanding is that the annual gain in reading and math is largest in grade 1 and declines every year through grade 12 (ie, simply that more of a kid’s level is “fixed”). so a gain of 0.2 SDs in grade 8 might mean “6 more months of learning” versus a smaller amount of additional learning in the younger grades. do you generally agree here, or am i misunderstanding?

b. if true, is it worth trying to adjust the effects from the 11 locations to account for grade level?

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