Why Power Laws? An Explanation from Fine-Grained Code Changes

Throughout the years, empirical studies have found power law distributions in various measures across many software systems. However, surprisingly little is known about how they are produced. What causes these power law distributions? We offer an explanation from the perspective of fine-grained code changes. A model based on preferential attachment and self-organized criticality is proposed to simulate software evolution. The experiment shows that the simulation is able to render power law distributions out of fine-grained code changes, suggesting preferential attachment and self-organized criticality are the underlying mechanism causing the power law distributions in software systems.