The Common Monitoring and Evaluation Framework (CMEF) for Rural Development Programmes (RDP) by the European Commission's Directorate General for Agriculture and Rural Development provides for common indicators to estimate effects of the respective measures. Their estimation has to rely on assumptions which may influence the results substantially and render them incomparable across measures. This caveat applies in particular in respect of net effects and of periods in which market prices fluctuate. The estimated effects of investment support measures can be used for benefit-cost analyses to compare the performances of measures. In the mid-term evaluation of the Austrian RDP these performances were found to differ widely. Using net (rather than gross) effects is likely to decrease the reliability of performance estimates but did not change the ranking of measures. Due to its positive effect on Gross Value Added, investment support renders private investments profitable and can be a profitable investment on its own. However, government intervention is justified only by the promotion of public rather than private goods.