A new approach to punishing women criminals could save millions of pounds a year, it has been claimed.
Findings from the New Economics Foundation (NEF) and the Prison Reform Trust said crimes could also be prevented by establishing a network of support and supervision centres.
As alternatives to jails they would help women offenders address the root causes of their offending, the interim findings suggested, by offering mental health treatment, help with drug and alcohol problems and advice on debt.
Ministers have yet to publish their response to Baroness Corston's review of female penal policy, which recommended taking thousands of women out of jail and setting up smaller centres.
Economic modelling in the report suggested that for every 2,000 women sentenced to prison in the UK for non-violent offences in 2005, a jail sentence imposed lifetime costs of £101.8 million. In comparison, community based sentences cost £82.5 million, it said.
Director of the Prison Reform Trust Juliet Lyon said: "These important findings highlight the price we pay for failing vulnerable women at risk of offending. Women's prisons are not full of serious and violent offenders, instead they are being used as stop-gap, cut-price providers of drug detox, mental health assessment and shelter, a dumping ground for those failed by public services."
She added: "This NEF briefing shows that the Corston review offers a blueprint for a system that protects public safety by making women less likely to reoffend and protects public money by concentrating on what will work in the long term to break the dreary cycle of crime."
Liberal Democrat justice spokesman David Heath said: "Women in the penal system have been ignored for far too long.
"The Government must not let its obsession with appearing tough stop the entirely sensible recommendations in the Corston review being implemented.
"The number of women in prison has doubled over the last decade, but there has been no corresponding rise in women committing more serious crime - nine out of 10 are convicted of non-violent offences. Women in prison, and society in general, would be much better served by smaller units spread around the country."
