Government policies are hindering attempts to integrate childcare and schools in England and Scotland, a report suggests.
Childcare can prove highly expensive
It says under-investment and treating care like a "commodity" have led to a fragmented and expensive service.
The research, carried out by London University's Institute of Education and the Children in Scotland agency, finds the system in Sweden - where "whole-day" schools provide childcare - more coherent.
Parents there pay up to six times less for pre-school places, the study says.
The Swedish whole-day schools were introduced to combine education and childcare in one setting.
They are increasingly linked with pre-school learning and care services for children from age one, under the leadership of the school principal.
The co-author of the study, Professor Peter Moss, said: "Sweden shows the value of working with long-term goals, sustained investment supported by high taxes and treating childcare as a public good, not a private commodity - this is a challenge for England and Scotland."
The report, published by the Policy Press, accuses Scotland of being "locked into central government's market-led childcare policy".
But a spokesman for the Scottish Executive said: "Our childcare strategy is clear that pre-school services should meet individual children's needs by preparing them for school and fitting in with families' work arrangements.
"We provide councils with funding to deliver this and expect it to be targeted at disadvantaged areas where appropriate.
"Our Integrated Early Years Strategy will be launched shortly. This will help ensure that all services for young children can work in partnership, including childcare, pre-school, health and social services, bringing together staff and services from the statutory, voluntary and private sectors."
A spokesperson for the Department for Education, which covers policy in England, said: "The Children Bill - which is currently being taken through Parliament - contains the legislation necessary for enabling these reforms and will bring together local authority education and children's social services."