Of all economic indicators, this is the one that best illustrates to little kids just how “great” the Great Recession was. According to the Original Tooth Fairy Poll, run by the Delta Dental Plans Association, the fetching price of a child’s tooth fell by 42 cents, to $2.10 from $2.52, between 2010 and 2011. The poll also claims that the price of a tooth tracks with the Dow Jones Industrial Average since 1998, when Delta Dental Plans started surveying the question. Skeptical? As odd an index as the Tooth Fairy’s asking price per tooth is, Delta Dental Plans isn’t the only organization tracking it. Visa, Inc., the credit card company, also does, finding in a survey released in July that the average tooth fetched 40 cents less in 2010 than it did in 2010.