The Economics of Open Source Software: An Empirical Analysis of Maintenance Costs

A quality degradation effect of proprietary code has been observed as a consequence of maintenance. This quality degradation effect, called entropy, is a cause for higher maintenance costs. In the Open Source context, the quality of code is a fundamental tenet of open software developers. As a consequence, the quality degradation principle measured by entropy cannot be assumed to be valid. The goal of the paper is to analyze the entropy of Open Source applications by measuring the evolution of maintenance costs over time. Analyses are based on cost data collected from a sample of 1251 Open Source application versions, compared with the costs estimated with a traditional model for proprietary software. Findings indicate that Open Source applications are less subject to entropy, have lower maintenance costs and also a lower need for maintenance interventions aimed at restoring quality. Finally, results show that a lower entropy is favored by greater functional simplicity.