Where effects accumulate and increase the overall effect. Examples are: snowflake growth where ice forms more easily on sharp tips, so any small growth grows further; earthquakes, where a very small release of tension in a fault can lead to a larger release in adjacent areas and culminate in an earthquake; citation rates, where the more citations a paper gains, the more it is seen and the more it is cited further.
Used on pages 49, 50, 51, 52
Also known as positive feedback effects