Richard Blewitt, chief executive of aid agency HelpAge International, marks U.N. International Day of Older People.

According to the U.N., this is a day when age should be celebrated, when older people's contribution to society should be recognised and applauded.

It's certainly a nice idea. Trouble is, I'm not sure the 100 million older people living on less than $1 a day feel particularly recognised right now. As they struggle to survive in the face of discrimination, marginalisation and a lack of economic and physical security, they probably feel pretty invisible.

Unfortunately, this is reflected in current international development policy. Initiatives such as the Millennium Development Goals focus largely on women and children, while global responses to HIV and AIDS target younger generations.

Older people are nowhere to be seen. Until this changes, the situation of older people living in poverty will continue to deteriorate.

The irony is that older people are the missing link in development. They are the backbone of society in many developing countries and play a vital role in supporting families and communities.

It's older people who facilitate the economic growth fueled by migration of younger generations to urban areas - staying behind to look after homes and children. It's older people, caring for the sick and the orphaned, who are at the frontline of the battle against HIV and AIDS. And it's older people who, without access to pensions, work long into old age to feed extended families.

Imagine what could be achieved then, if older people were not only recognised in international development policy but actively supported, if they were seen as a resource, rather than a burden on society.

Let's take poverty reduction. Around one in 12 people in developing countries is over the age of 60. Can any poverty reduction strategy be truly effective without including this significant proportion of the population?

Access to social security is absolutely vital to lifting older people out of poverty.

Social pensions, where they exist in developing countries, have proved extremely successful in this regard, with the benefits going beyond older people themselves. For those supporting extended families, particularly orphans of AIDS, a pension provides financial resources which can help ensure healthcare and an education for the next generation. Pensions can also help to mitigate the impact of sudden shocks like rising food prices, and stimulate local economies.

Targeting older people with income generation activities has a similar effect. Most older people want to work, to retain independence, dignity and security in old age. Yet all too often they are sidelined in income-generating projects, written-off as a risky investment.

Where older people have been given access to these initiatives, their business skill quickly becomes clear; they invest the money in farming or a business to create long-term income security.

And what about HIV and AIDS? Currently, several of the indicators used by UNAIDS to monitor the impact of the pandemic don't even include people over the age of 50. This fails to recognise older people both as a group at risk of infection (yes, the over-50s do have sex!) and their invaluable role as carers.

As a result, the agency which is leading countries in their response to HIV and AIDS has no data on how it is affecting older people. Without this, older people are excluded in policy and programming responses, and the overall strategy remains flawed.

So, including older people in development policy is crucial if there is to be real progress on some of the world's biggest issues. This isn't just common sense though, it's essential if we are to effectively prepare for what, after climate change, is the next big challenge of our times.

The world's population is ageing fast. By 2050, one in five people will be over the age of 60, with the fastest growth in developing countries. Unless the international community starts supporting older people now, we'll be unable to harness their massive social and economic potential for the future.

Find out more on HelpAge International's website.

Reuters AlertNet is not responsible for the content of external websites.