About ten months ago, I put an argument for a convertible tax allowance on the blog – here is the link. The New Economics Foundation has just floated a very similar idea, in a report called Nothing Personal. The main difference between their proposal and mine is that they are proposing not an optional conversion, but a universal one. That would have the advantage of ensuring coverage, but it would also have two large disadvantages. One is that it would call for much more extensive direct administration, because it doesn’t use the existing PAYE system in the same way. The other is that the personal allowance would be reduced to zero, requiring declaration of every penny earned.