Is Cloned Code More Stable than Non-cloned Code?

This paper presents a study on the stability of cloned code. The results from an analysis of 200 weeks of evolution of five software system show that the stability as measured by changes to the system is dominated by the deletion of code clones. It can also be observed that additions to a systems are more often additions to non-cloned code than additions to cloned code. If the dominating factor of deletions is eliminated, it can generally be concluded that cloned code is more stable than non-cloned code.