This first edition of the OECD Pensions Outlook takes a close look at the two main trends in pension design observed over the last two decades: first, the introduction of reforms to pay-as-you-go (PAYG), public pension systems such as later retirement and automatic adjustment mechanisms to pension benefits to improve the financial sustainability of these systems; second, the growth of funded private pension arrangements complementing PAYG public pensions. These developments are interlinked, as many pension reforms have ultimately led to a reduction in the replacement rate offered by PAYG public pension systems, increasing the need for later retirement and complementary forms of pension provision.