Government plans to extend financial and property rights to unmarried couples could lead to fewer marriages and births in England and Wales, according to a new report drawing on the experience of Finland.
In its new report, ‘Finnishing Marriage? Lessons from Finland’s cohabitation reforms’, the Centre for Social Justice (CSJ) has warned that proposals to automatically give some cohabiting couples additional legal entitlements over property and finances risk having unforeseen effects on marriage, fertility and family formation.
Under reforms being considered by the government, couples who have lived together continuously for at least three years, or who live and have a child together, could acquire new financial and property rights without having to marry or formally opt in to the arrangement.
The government has claimed that the changes are not expected to significantly influence people’s decisions about whether to marry, cohabit or start a family.
However, the CSJ challenges that assumption in its new report, which examines what happened after Finland introduced legal protections for cohabiting couples in 2011.
Finland’s legislation was narrower than the proposals being considered for England and Wales.
It generally covered couples who had lived together for at least five years or where a couple shared a child, while property ordinarily remained with its legal owner and there were no equivalent automatic inheritance rights.
Using neighbouring Nordic and Baltic countries for comparison, the CSJ estimated that Finland’s female first-marriage rate was 23% lower than it would otherwise have been seven years after the changes.
The report says the decline in marriage was not accompanied by greater stability among cohabiting households. Instead, by 2020, the share of two-adult working-age households was estimated to be 16% below the level expected without the reform, with the divergence becoming more pronounced from around 2014.
The CSJ also identified a link between the introduction of the reforms and Finland’s falling fertility rate, which it concluded was 21% lower by 2018 than it would have been without the change. Finland’s total fertility rate decreased from 1.86 in 2010 to 1.37 in 2020.
The report points to separate academic research suggesting that 42% of the decline in first births was linked to cohabiting couples having fewer children.
The CSJ then applied the estimated effects in Finland to England and Wales to assess what might have happened if similar reforms had been introduced in 2011.
The think-tank estimates that there could have been around 111,000 fewer marriages between 2012 and 2023, including nearly 25,000 fewer in 2023 alone.
Using the higher fertility levels of earlier years, it calculated an average of 86,000 fewer births a year from 2012, while applying the model to more recent birth figures would amount to 75,000 fewer births a year from 2021.
Instead of the actual fertility rate of 1.41 in 2024, it predicts that the rate would have been 1.25 if the reforms had been introduced in 2011.
Since the UK’s proposals go further than Finland’s, the CSJ argues that the government’s assumption of “behavioural neutrality” is unsupported by its statistical findings and says this makes it particularly important that ministers consider possible effects on behaviour before proceeding with changing the legal distinction between marriage and cohabitation.
Shadow Justice Secretary Nick Timothy MP argued in the report’s foreword that the changes risk weakening the distinction between marriage and cohabitation.
He stated: “Strong societies depend on strong families. That does not mean ignoring the realities faced by couples who live together or pretending marriage solves every social problem. But it does mean recognising that law shapes behaviour, institutions matter, and strong families are built on choices people make and keep.
“The new Prime Minister promised change from the consensus he inherited, and rethinking these cohabitation reforms would be a good place to start. Adults should have choice over the legal consequences of their relationships.
“The right response to changing how people live is not to erase the distinction between the choices people make, but to respect it.”
Deputy Research Director at the CSJ, Sophia Worringer, described Finland as a warning for ministers considering the reforms.
“Many people in cohabiting relationships do not want to get married, and the government should not impose marriage-style financial obligations on them by stealth,” she said.
“The lesson from Finland is clear: marriage fell, cohabitation declined, and fertility dropped. Andy Burnham should scrap any plans to follow its example.”
The findings come amid wider concern about Britain’s falling birth rate and an ageing population, with a smaller working-age population expected to face increasing pressure to support spending on pensions and public services.
The CSJ questioned whether the proposed changes command significant public support.
Polling of 1,515 UK adults conducted by JL Partners in June found that 59.3% believed marriage should remain a choice instead of automatically gaining similar rights through a certain period of cohabitation. Only one in 10 disagreed.
Less than a quarter (24.3%) regarded changing cohabitation law as a government priority, and more than half (56.2%) said cohabitation alone should not create financial or property claims between partners, compared to only 13% taking the opposite view.
The report stated: “Over 4 in 10 of the public are concerned that an active opt-out process could cause issues in otherwise happy relationships compared to 14.3% who disagree.”
Dr Tony Rucinski, of the Coalition for Marriage (C4M), welcomed the report, arguing that marriage currently provides a clearly identifiable point at which couples knowingly acquire legal rights and responsibilities.
“Marriage is a bright line, everyone knows who crossed it and when, including the couple themselves – one public day, chosen, witnessed and dated,” he said. “This scheme would replace the line with a fog.”
He continued: “‘Rights’ that arrive unseen at three years, or sooner where a child is in the household. ‘Rights’ you can escape only by deed, with two solicitors. ‘Rights’ narrower than marriage while you live together, yet identical to it when you die. The bright line is what protects; the fog is what this consultation proposes.”
Dr Rucinski accused the government of failing to consider the potential effects on marriage, saying: “Their impact assessment never once assesses what the scheme would do to marriage.”
He added that public opinion does not suggest an appetite for the changes.
“A government that paused this now would be siding with the public and with the evidence at the same time,” he said.
