In most OECD countries, public spending rose steadily as a share of GDP over the past decades to the mid-1990s, but this trend has since abated. The spending pressures stemming from the continued expansion of social programmes have been partly compensated by transient or one-off factors. Pressures on public spending, however, appear likely to intensify, in particular as a consequence of ageing populations. Since most OECD economies have very little scope for raising taxation or debt to finance higher spending, reforms to curb the growth in public spending while raising its cost effectiveness are now required. Based on detailed country reviews for over two-thirds of OECD countries, this paper identifies three main areas for action: the budget process; management practices; and the use of market mechanisms in the delivery of public services ...