15 The Lindy effect and NBA franchises
This chapter covers
- 80-20 rule
- Pareto charts
- Violin plots
- Paired histograms
The Lindy effect, or Lindy’s law, suggests that non-perishable items, such as a book in print or a business, have life expectancies equal to their current age. For instance, if The Great Gatsby has been in print for 100 years we can expect it to remain in print for another 100 years. The concept is named after a former delicatessen in New York City named Lindy’s that nonetheless remained open for nearly a century. The Lindy effect does not apply to human beings, fruit, or other perishable items; after all, we can’t expect a man aged 75 years to live another 75 years, or a banana to stay ripe indefinitely.
From a statistical perspective, the Lindy effect follows a right-skewed, or positive-skewed, probability distribution; which is to say the distribution of a numeric variable over a continuous interval peaks when x is close to 0 and then tapers as x increases. Our first visualization (see figure 15.1) demonstrates this effect; it’s a ggplot2 density plot that displays the distribution of NBA franchises between 1946, when the NBA was founded, through 2020 (where the number of franchises equals unique team names between cities, states, and nicknames).