IFS analysis of tax and benefit changes
The Institute For Fiscal Studies (IFS) says that the entire package of tax and benefit changes coming into force by 2014-15 is clearly regressive, including the tax increases put in train by Labour.
The Treasury analysis for the spending review document, which suggests otherwise, excludes a third of the benefit changes planned by the government and does not go up to 2014-15. The changes excluded by this are clearly regressive - they have the greatest effect, relative to income, on people at the lower end of the income scale.
The IFS also notes the inconsistency in the Treasury analysis - that it should make the heroic assumptions necessary to model the effect of, for example, the pupil premium across households, while making no effort to calculate the effect of removing council tax benefit and cutting housing benefit. The IFS says both are difficult to do and sensitive to the assumptions used - but benefit changes are much easier.