As the Institute of Fiscal Studies have published a very useful analysis of the policy, which is worth reading in full, which allows us to look at the detail.
Here are some of the main points about the Conservative policy:
* Three out of ten married couples would gain from the policy
"In total, we estimate that 4.0 million out 12 million married couples in Britain".
The other 8 million married couples fall into one of the three categories of those who the Conservatives exclude from benefitting from the policy.
- Married couples where both partners earn over £6555.
- Married couples where either partner earns enough to pay the higher rate of tax.
- Married couples where neither partner earns over £6555.
* Only one in three of those who gain are couples with children.
The IFS writes:
"If encouraging marriage is seen as desirable primarily for the impact it has on child development, it is not clear that a policy where dependent families make up more than a third of beneficiaries and receive 31% of the gains is well targetted. In fact, only 35% of the families who gain from the policy have children, and only 17% have children under 5".
One in three married couples with children gain - and one in five of all families
So the IFS report that 1.4 million married couples with children will be among the 4 million couples who benefit.
By, my own calculations - comparing their policy analysis to 2001 data on types of UK household, so this might be treated as a rough estimate - the policy would benefit just under one in three married couples (31%) with dependent children, and around one in five (19%) of all families with children.
In 2001, there were 7.2 million families with children, of whom 4,559,060 were married couple families, 814,939 were cohabiting couple families, 1,664,081 lone mother families and 182,514 lone father families. The married couple and cohabiting figures each include over 300,000 stepfamilies within those categories.
* "Complex and expensive"
Back to the IFS:
"The most striking feature of the policy is that it significantly complicates the income tax system ... and will surely be complicated to understand and complex to administer, and this coust must be considered in addition to the direct cost of the policy".
"Simpler ways to provide support to low- and middle-income married couples would include introducing a married couples 'premium' into working tax credit and pension credit".
This last IFS suggestion would enable the Conservatives to 'recognise marriage'; to stick to the policy of excluding higher-income households; but to avoid the "stay at home" bonus which is now the defining feature of their allowances' approach.
So why not? The most obvious reason would be that tax credits are Gordon Brown's invention, and so the Conservatives seek to denigrate them, while also saying they are committed to keeping them for most families. The irony is that not using the tax credits scheme they lambast for its complexity has required the Conservatives to come up with an alternative which the IFS notes is yet more "complicated, confusing, untransparent and byzantine").
Stephen Tall at LibDemVoice has some very good examples of how the policy offends fairness intuitions. I have argued that matters particularly because the policy is presented as being more about the symbolism than the money.
However, one does not particularly need to use emotively framed cases about the personal behaviour of those who do or don't benefit - though these will be effective on the campaign trail - to see how the policy has little rhyme, reason or coherence as a symbolic tax change. Even among married couples, the is your marriage recognised? question throws up a wide range of fairly odd results:
A relatively affluent middle-income family with the husband earning £40,000 and the wife not working is recognised and would benefit.
A similarly affluent middle-income family with the wife earning £25,000 and the husband earning £15,000 is not recognised and would not benefit.
A lower middle-income married couple where the husband earns £18,000 where the wife works a couple of days, earning £7,500 per year, while juggling work and looking after children is not recognised and would not benefit.
A pensioner couple with that same balance of income and no dependent children is recognised and would I think benefit (because the pensioner income tax threshold is higher).
A lower-income married couple without children, where one partner works full-time and earns the minimum wage and the other does not work is recognised and would benefit.
A lower-income married couple with a child who both earn £10,000 a year is not recognised and would not benefit.
Two other things I would be interested to find out:
1. How many people in civil partnerships are included in practice?
Much is being made of the symbolic inclusion of civil partnerships. But it will be interesting to investigate how far that is practically the case. I am not sure what data or surveys exist on the socio-economic profile of civil partnered couples: anecdotal evidence suggests it could well be that fewer than 1 in 3 have the household profile being supported here.
2. Will the exclusion of higher rate taxpayers be criticised from the pro-marriage right?
The one ProgCon element of the policy is that it excludes those earning over £44,000 to avoid a highly regressive distributional effect. (However, the most striking thing about the IFS distributional table is the scale of changes involved).
But this means it leaves out the "coping classes", those in the top 5-10% of the income range which the Daily Telegraph thinks of as the squeezed middle, with households on around £88,000 who "feel so damned poor". Almost all of those keenest to advocate pro-marriage policies in the media would be in that income bracket - but perhaps they will prove be no less keen on a marriage tax break which cuts them out.
Fiscal conservatives are, naturally, somewhat in despair at the policy, as today's scathing The Times highlights.