Two-fifths of people over 55 are from the middle-class, white-collar, ABC1 social groups, constituting a "huge and affluent market". But many older skilled workers - the C2s - also have considerable disposable income.
The report, from the market intelligence group Maps, says that "greys" are becoming more mentally and physically active and are spending more time and money on holidays, eating out, visiting friends, gardening and home improvements. For example, they areone of the biggest buyers of winter sun holidays.
By contrast, parallel research by Maps on the "youth" market - young adults aged 15-24 - suggests that a "sizeable minority" are not interested in social life, partly because they are worried about jobs and partly because social life for many teenagers "means isolating themselves for long periods to play computer games".
A survey by NOP of the 15-24 age group found that only 37 per cent said "enjoying my free time socially" was one of their biggest priorities, along with physical well-being (42 per cent) and "having enough money" (37 per cent). Their natural desire to socialise may be "tempered by a growing realism about future prospects", the report says.
Thirty-five per cent, for example, said their main priority was getting training or qualifications and 28 per cent listed "enjoying my work".
Despite the leisure industry's "obsession" with youth, the over-55s have far higher levels of discretionary income, Maps says. Owner-occupation stands at 66 per cent, more than half have paid off their mortgages, and the 50-65 age group, in particular, are heavy spenders on leisure.
However, they are increasingly discerning, demand value for money and feel patronised or insulted if they are targeted simply on the basis of age. They have been brought up in the consumer society "and are unlikely to move into the stereotypical role of the over-55s of the past".
NOP research found that 61 per cent of respondents in the survey spent most on newspapers, magazines and books, followed by gardening (45 per cent), visiting friends and family (33 per cent), eating and drinking out (28 per cent), insurance policies (28 per cent), home improvements (26 per cent), and UK holidays (22 per cent).
The most affluent group are looking for mainstream holidays, not those targeted at older people. The over-45s, for example, account for 55 per cent of the winter sun market; cruises are highly popular.
In 1961 there were 16 million people over 50 in the UK. By 2021 there will be 22.5 million - an increase of 40 per cent against an overall population rise of 15 per cent.
The proportion of over-50s will grow from 31 per cent today to 37 per cent in 2021.
However, the research also points out that the least affluent group, the unskilled workers and state pensioners, still outnumber the better-off. Since life expectancy is increasing, this group poses serious financial and social problems.
"Grey" Market and "Youth" Market reports; Maps, 4 Crinan Street, London N1 9UE; £495 each.