Abstract
This article investigates the performances of family firms in general, family involvement in management (FIM), and ownership in particular. Using a sample of 495 Dutch non-listed firms, this article finds an inverse U-shaped relation over the age of the family firms in general which seems to be explained by FIM. There is also an indication that the effect of family involvement in ownership (FIO) is insignificant. This article provides useful insight into the potential to allow for interaction between time, and also indicates that size has the same potential to explain the relative performance of family firms versus non family firms.