Single men in their 40s are in such demand that they suffer from a "hotness delusion syndrome", a demographer claims.
Their rarity compared to women of the same age means they still receive lots of attention - leading to a delusion about their sex appeal, KPMG demographer Bernard Salt said.
"He can be balding and paunchy. And when he looks in the mirror he doesn't see balding and paunchy, he sees taut, trim and terrific."
He said the female attention made some middle-aged men think they were "pretty damned hot".
"Well, you may well be pretty damn hot, but you need to take into account the demographics - you're about the only thing going around."
Mr Salt said at age 44, there were 15 per cent fewer available males than females in Australia.
Paul Callister, from Victoria University's Institute of Policy Studies, has studied New Zealand's "missing men" and confirmed a similar trend exists here. For every woman aged 40-44 there were only 0.92 men.
Mr Salt said another factor was that men who divorced typically re-partnered more quickly than women.
"To account for this syndrome ... when [men in their 40s] look in the mirror, they need to discount their hotness by the proportion by which there are more women than men," he said.
Christchurch man David Smith, 42, has been single for two years and conceded there was some truth to the claims.
Mr Smith said he had seen some men his age acting in an arrogant manner at speed dating events.
"But having said that, women are smart, men are dumb. They're not settling for anything less, if they don't like you they'll just walk away.
"But these guys say, 'Oh well, if it's not you, it's someone else'."
Verity Molloy, the director of speeddate.co.nz, said she had also encountered the syndrome.
"I have got an excess of women aged 40-plus on my database, and I'm forever chasing the men to book for events. They know they're in hot demand."
Mr Salt said the lack of middle-aged bachelors had aided the "rise of the cougar" - women in their 40s pairing up with younger men.
"Women are empowered these days and will seek out a relationship wherever they see fit, and that could well be women in their 40s marrying someone in their 20s.
Ms Molloy agreed.
"It's not like we want quantity, we want quality ... just because they're in their mid-40s, it doesn't mean they're a good catch," she said.