The UK's city centres are being taken over by young, single people, according to research published on Wednesday.
Liverpool's city centre population grew by 40% in the 90s
But the study of Dundee, Liverpool and Manchester found despite huge rises in their populations, it is harder for families to find the space they need.
The Institute for Public Policy Research's Centre for Cities was studying city living outside London.
The report will be launched by Warren Bradley, Liverpool City Council leader and Tom Bloxham, Urban Splash chairman.
The report said planners and developers should focus on the "doughnuts of deprivation" in nearby inner suburbs which can provide better accommodate for the schools, healthcare, parks and shops that people need when they start families.
Liverpool's city centre population grew by 40% in the 1990s with two thirds of the current population of 15,000 made up of students and young professionals.
Twenty-eight percent of the population are aged 20-24 compared with 6% nationally.
Manchester has experienced a massive rise in city centre living with a 300% increase in the 1990s - people living in the centre are twice as likely to be single as the national average.
Dundee's city centre growth has been spurred by an increase in the number of students with a population increase of 100% in the 1990s.
Two thirds of the current population of 3,000 are students but the city needs to create more jobs to keep them, according to the report.
"Young, single people have led the return to the city," said report author Max Nathan.
"But families and older people prefer neighbourhoods with houses, parks, schools and healthcare.
"This is a great opportunity for planners and developers to improve deprived areas near the centre, rather than passing on the cost of family infrastructure in city cores."
Mr Bloxham, of developers Urban Splash, said: "The city centre living phenomenon has been with us over 15 years now.
"But as city centres have recovered, many areas nearby have stayed the same. Regenerating these inner ring neighbourhoods is the big priority for the decade ahead."