Many school districts around the U.S. are moving to a four-day school week to retain teachers. Districts that don't want to raise taxes to pay teachers more are using the long weekend as an incentive.

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Contagion - one district does it, then the neighboring district does it, too. There are entire clusters now in Texas, Missouri, Montana, where every district anywhere near you only offers four days of instruction. There is no other option. And when you get these cluster contagion effects, schools lose their competitive advantage.