Aging poses a serious challenge to OECD(Organization of Economic Co-operation and Development)countries，in particular，how to pay for future public pension liabilities. And early retirement places an__1__burden on pension financing. There is no easy solution，but__2__retirement could help.
    Early retirement may seem like a worthy individual goal，but it is a socially__3__one，and makes the present public pension system difficult to sustain for long. The__4__reason is that more people are retiring early and living longer. That means more retirees depending on the__5__of those in work for their income. The__6__is worrying. In the next 50 years，low fertility rates and__7__life expectancy in OECD countries will cause this old-age dependency rate to roughly double__8__size. Public pension payments，which afford 30-80% of total retirement incomes in OECD countries，are__9__to rise，on average，by over three percentage points in GDP and by as much as eight percentage points in some countries.__10__is the pressure on pension funds that there is a danger of today‘s workers not getting the pensions they expected or felt they__11__for.
    Action is needed，__12__simply aiming to reduce the__13__(and cost)of public pensions，or trying to__14__the role of privately funded pensions within the system，though necessary steps，may be__15__to deal with the dependency challenge. After years of__16__early retirement schemes to avoid__17__and higher unemployment，many governments are now looking__18__persuading people to stay in work until they are older. Surely，the thinking goes，if we are healthier now and jobs are physically less__19__and unemployment is down，then perhaps the__20__rate should rise anew.