For decades, insurance giant Delta Dental has run an annual poll tracking the average amount of money the "Tooth Fairy" leaves under children's pillows. Surprisingly, this "Tooth Fairy Index" has historically shown a strong correlation with the performance of the S&P 500 stock market index. When the economy is booming and stock prices rise, parents tend to leave significantly more money per tooth, making the fairy a reliable indicator of consumer confidence.
Ancient Roots and the First Tooth Fees
The modern ritual of exchanging a lost baby tooth for money is not an entirely modern invention, though its contemporary form has evolved considerably over centuries. In early Scandinavian and Northern European folklore, teeth held distinct spiritual and protective qualities. In the Norse tradition, an established custom known as the tand-fé, or 'tooth fee', involved paying a small gift or sum of money to a child upon the loss of their first deciduous tooth. These fallen teeth were considered lucky charms and were sometimes worn around the necks of warriors or buried to ensure safety and strength.
Across wider Europe, rituals surrounding lost teeth were heavily intertwined with protective magic. In various agrarian cultures, parents disposed of discarded baby teeth by burying them in the soil, throwing them into fires, or feeding them to animals. These protective measures were believed to keep witches or malevolent spirits from using the discarded bodily fragments to cast curses on the child. Alternatively, offering the tooth to an animal, particularly a rodent known for strong and continuously growing teeth, was believed to encourage the growth of sturdy adult teeth.
From Rodents to Fairy Godmothers
The transition from ritual tooth disposal to an anthropomorphic benefactor emerged through European literature and folklore, particularly the legend of the tooth mouse. In the late seventeenth century, French author Madame d'Aulnoy published a fairy tale titled 'La Bonne Petite Souris' (The Good Little Mouse). In the story, a benevolent mouse transforms into a fairy to help a captive queen by knocking out the teeth of an evil king and defeating him. This tale helped popularize the idea of a nocturnal, tooth-gathering creature across Romance-language cultures.
This concept remains dominant in many parts of the world today. In France and French-speaking regions, the character is known as 'La Petite Souris', while across Spain and Latin America, children place their teeth under their pillows for 'El Ratoncito Pérez' or simply 'El Ratón de los Dientes'. The creature typically takes the tooth while the child sleeps and leaves coins or small gifts in return, serving the exact same narrative function as the winged tooth fairy of English-speaking cultures.
The Rise of the American Tooth Fairy
The distinct, winged Tooth Fairy known in North America and Britain coalesced gradually during the early decades of the twentieth century. One of the earliest known print references appeared in a 1908 edition of the Chicago Daily Tribune, which featured a household advice column mentioning the tooth fairy as an incentive for reluctant children to allow loose teeth to be pulled. In 1927, Esther Watkins Arnold published an eight-page playlet titled 'The Tooth Fairy', which helped introduce the concept into elementary classrooms and popular culture.
By the mid-twentieth century, as post-war suburban family life expanded and popular media increasingly featured fairy characters, the Tooth Fairy became a standard fixture of American childhood. The folklorist Rosemary Wells, who conducted extensive research into the tradition and established a Tooth Fairy museum in Illinois, observed that unlike Santa Claus or the Easter Bunny, whose appearances are tied to fixed calendar holidays, the Tooth Fairy operates entirely around individual biological milestones, visiting a household repeatedly over several years.
The Tooth Fairy Index and the Stock Market
As the tradition solidified into an almost universal monetary exchange in the United States, dental insurance providers began looking at the custom to gauge dental health awareness and family habits. In 1998, the insurance company Delta Dental launched an annual poll tracking the average cash payout left beneath pillows across the nation. Over decades of data collection, researchers and market analysts noticed an unexpected pattern: the average payout per tooth consistently mirrored broader macroeconomic trends.
Dubbed the 'Tooth Fairy Index', the annual average payout has exhibited a notable correlation with the performance of the S&P 500 stock index. During periods of economic growth and rising stock values, parents tend to leave more money beneath pillows, whereas during recessions or market downturns, the average payout typically flattens or declines. The poll has shown that the exchange of a child's baby tooth serves as a micro-level mirror of adult consumer sentiment and household liquidity.
Discretionary Cash and Economic Psychology
The correlation between tooth fairy payouts and financial indices highlights how discretionary household spending operates in everyday life. Unlike fixed expenses such as rent, groceries, or utilities, gifts left by mythological figures represent purely discretionary cash transactions. Because these payments are made on impulse from whatever bills or coins parents happen to carry, the amount left under a pillow directly reflects a parent's perceived financial comfort and immediate liquid cash availability.
The index also captures the effects of inflation and changes in cash circulation over time. Where children in the mid-twentieth century typically received nickels, dimes, or quarters, contemporary payouts frequently involve single or multiple dollar bills, with special bonuses occasionally awarded for the first lost tooth or for teeth lost without incident. When general prices rise, the baseline expectation for small cash gifts rises alongside them, ensuring that the tooth fairy's gifts reflect the current purchasing power of the currency.
Cultural Purpose and Behavioral Function
Beyond its humorous standing as an informal economic indicator, the Tooth Fairy tradition serves important psychological and developmental roles within families. The loss of baby teeth represents a visible and sometimes frightening physical change for young children. Transforming the physical loss of a body part into a celebrated milestone accompanied by a monetary reward helps alleviate fear, giving children a sense of agency and pride in their physical maturation.
Simultaneously, the ritual has been leveraged by parents and health practitioners to reinforce dental hygiene. Because the myth often posits that cleaner, cavity-free teeth are valued more highly by the fairy, the custom provides a tangible, recurring motivation for children to brush and care for their teeth. Whether through a fairy, a mouse, or ancient protective fees, the underlying social mechanism remains unchanged: comforting the child, celebrating growth, and marking a major step toward adulthood.
Key takeaways
•The Tooth Fairy Index, tracked annually by Delta Dental since 1998, shows that average cash payouts per tooth historically mirror the performance of the S&P 500.
•The tradition evolved from ancient European practices, including the Norse tand-fé (tooth fee) and eighteenth-century French tales of benevolent tooth-gathering mice.
•Because pillow payouts represent purely discretionary cash spending, they serve as a sensitive micro-indicator of parental financial comfort and broader consumer sentiment.
•Across different cultures, tooth-gathering figures like the Tooth Fairy and El Ratoncito Pérez help ease children's anxiety around physical bodily changes while encouraging dental hygiene.