Falling birthrates, increased life-expectancy and the approaching retirement of the so-called "baby boom" generation mean that the population balance is altering.
In 1998 just 32.4% of Britons were aged over fifty. By 2021 that proportion is expected to have burgeoned to over 40%. What effects will that have on the economy, public health strategy, the planning of housing and infrastructure?
I asked the public for their views and interviewed experts from a group called 50-50 Vision, who have the task of proposing strategies to anticipate and cope with the change.