A million more young adults in the UK are living with their parents than were two decades ago, research suggests.
A quarter of 20- to 34-year-olds do so, the study, by think tank Civitas, says.
This rises to 41% in London, where housing is most expensive, but falls where it is cheapest – north-east England (14%) and Yorkshire and the Humber (17%).
And for 23-year-olds across the UK, the proportion living with parents has risen from 37% in 1998 to 49% in 2017.
Civitas editorial director Daniel Bentley said: “As owner-occupation and social housing have each become more difficult to enter, hundreds of thousands of young adults have taken one look at the high rents in the private rented sector and decided to stay with their parents a bit longer instead.”
He added that it was essential that the government took this into account when forecasting future housing need.
The study also suggests youngsters who do move out are much less likely to live on their own than they were in the late 1990s.
Single-person households have dropped to 30% in recent years, it says.
This is in stark contrast to most of northern and western Europe, the report says, where single living has been increasing rapidly.
In France and the Netherlands, 35% of households are single-person. And this rises to more than 40% in Germany and Denmark.