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Thank you for summarizing this work here, Dr. Groseclose.
I can’t help but wonder if the objections to the “mismatch” theory come from people who consider the value of credentials to be greater than learning. If the credential is the only thing that matters, then it doesn’t matter if one group gets less out of the educational opportunities of elite schools. They are still in the elite.
Mismatch theory would then be a direct threat to both desired outcomes and self worth. That would explain why the results in the OP are being ignored by the “soulless minions of orthodoxy“.