Presentation on theme: "A problem with the Long Tail (Although an amazing number of things are powerlaws, a lot of things arent. How can you tell the difference?) (Read the text."— Presentation transcript:
A problem with the Long Tail (Although an amazing number of things are powerlaws, a lot of things arent. How can you tell the difference?) (Read the text in the notes panel at the bottom for narration)
Shown another way
The Missing Market
Source: Morris Rosenthal
Examples of phenomena that follow powerlaw distributions Species distribution among plants Square footage of Alaskan Inuit homes Forest fires, by size Cities, by population Death toll in wars Earthquakes Word use Number of papers published by scientists
Examples of phenomena that follow lognormal distributions Concentration of elements in the earth's crust Latent periods of infectious diseases Survival times after cancer diagnosis Distribution of chemicals in the environment (including pollution) Species distribution among moths and diatoms Crystals in ice cream Length of words in spoken conversation
Whats the difference? Powerlaws: created by preferential attachment in scale-free networks.
Lognormal distributions: created by "proportionate effects" (like growing by a proportion of your weight).
Question Assuming it all comes down to network effects, how can you predict whether the natural shape (free of bottlenecks and other scarcity distortions) is a powerlaw or a lognormal distribution?