The Friday File: During 2022, the average amount left by the Tooth Fairy per lost tooth was $6.23, up from $5.36 in 2021, a solid rise of 16%. The Tooth Fairy was most generous in the South leaving $6.59, followed by the West at $6.25, the Northeast at $6.14 and the Midwest at just $5.63. That cavity size $0.96 gap between the South and Midwest looks ripe for arbitrage.