[en] We simulate different reform scenarios of the Belgian pension system using a micro-simulation approach. Using a rich administrative dataset with extensive information on individual earnings histories, we evaluate the impact of the scenarios for the individuals as well as the system as a whole. Our main metric for these analysis is the notion of accrued to date pension rights, i.e. the pensions rights that would be due if the system were shut down today and all accrued rights under current legislation were honoured. Our analysis illustrates that partial reforms have limited effects, both in distributional and in fiscal terms. To achieve more substantial effects, a more comprehensive approach is needed. Regional differences within the country are mostly due to differences in regional GDP rather than the pension system itself.