Reforming pensions is one of the biggest challenges of the century. All OECD countries have to adjust to the ageing of their populations and re-balance retirement income provision to keep it adequate and ensure that the retirement income system is financially sustainable. Demographers have been warning us for some time that ageing is looming and that when it strikes populations and workforces will rapidly age. But many governments preferred to ignore the call for reform and cling to the hope of postponing solutions beyond the next election or claiming that rather painless remedies could be found. Immigration of younger workers, more women in work and higher productivity were put forward in the hope that more painful solutions could be avoided. All of these factors can certainly help to cope with ageing and especially with the financing of pensions but the increases necessary to compensate for ageing are so large that one cannot rely on them alone. Most OECD countries have realised this and have undertaken numerous reforms during past years. But pension reform is a difficult task. It involves long-term policy decisions under uncertain conditions and often the likely impact of these decisions on the well-being of pensioners is not spelt out clearly. More than most other areas, pension reform is a highly sensitive topic. Not only does it lead to heated ideological debates, but it makes people protest in the streets, and even forces governments to retreat from needed reforms. As people working on pension reforms around the world, we at the OECD Secretariat are asked time and again for the “right” solution to the problem. Which country does it the best way, which country is doing the worst job, which systems are the most generous, will it be possible to reform without increasing pensioner poverty, and will countries be able to pay for the promises they are making? There are no simple answers to these questions. National retirement-income systems are complex and pension benefits depend on a wide range of factors. Differences in retirement ages, benefit calculation methods and adjustment of paid-out pensions make it very difficult to compare pension policies across countries. Another problem is that life expectancies at retirement differ from one country to another, which means that some countries will have to pay pensions for a much longer period of retirement than others. As a result national debates are often full of misleading claims regarding the generosity and affordability of other countries’ pension arrangements. International comparisons to date have focussed mostly on the fiscal aspects of the ageing problem. But much less attention has been paid to the social sustainability of pension systems and the impact of reforms on the adequacy and distribution of pensioner incomes. But these aspects are also crucial if countries want to attain the dual objective of promising affordable pensions and preventing a resurgence of pensioner poverty. This report presents the first direct comparison of pension promises across OECD countries. It provides a novel framework to assess the future impact of today’s pension policies, including their economic and social objectives. It takes account of the detailed rules of pension systems but summarises them in measures that are easy to compare. Pension benefits are projected for workers at different levels of earnings, covering all mandatory sources of retirement income for private-sector workers, including minimum pensions, basic and means-tested schemes, earnings-related programmes and defined contribution schemes. Another novelty is the inclusion of the large effects of the personal income tax and social security contributions on living standards in work and in retirement: all indicators are presented gross and net of taxes and contributions. The framework can be used in different ways. As it is flexible to changing assumptions, the impact of policy reforms and economic developments on pension entitlements can be simulated. It can provide answers to questions such as what would happen if a country switched from wage to price indexation of pensions, or changed the benefit accrual rate. It can also inform on the impact of changes in economic growth, interest rates, wage growth or inflation on pensions of future retirees. The OECD will use the framework to monitor pension reforms in member countries by updating this report regularly. This report is the first in a biennial series which will be produced in co-operation with the European Commission. Public opinion on pensions is changing. People are realising that a shrinking number of young workers will have trouble paying for more and more pensioners. Time has come to open a frank debate among all members of society and address the question of how the cost of ageing should be distributed in each society. Our publication aims to contribute to this debate by shedding more light on the social and economic implications of pension reform.