OECD countries need to encourage older people to delay retirement, otherwise population ageing will result in slower growth and higher taxes, the organisation said in a report. "On the basis of unchanged (work) patterns, OECD analysis shows GDP growth per capita in the OECD area could shrik to around 1.7 pct per year over the next three decades, about 30 pct below the average annual rates witnessed between 1970 and 2000," it said. Currently, fewer than 60 pct of 50-64 year olds have a job in OECD countries, compared with 75 pct of the 25-49 age group. If these employment rates do not change, population ageing will mean that the number of older inactive people will almost double to just over 70 pct of the number of workers by 2050, from 38 pct in 2000, it said "This, in turn, would lead to higher taxes and/or lower benefits, coupled with slower economic growth," it said. It said many public policies and workplace practices discourage older people from carrying on working, and these now need to be reversed. "Such policies and practices are relics of a bygone age and unsustainable at a time when population ageing is straining public finances and holding back higher living standards," it said. Governments should ensure that pensions and other welfare arrangements encourage rather than discourage work at older ages, it said. And the practice of mandatory retirement in firms should be questioned, it said