Miliband's
IFS document on the living wage makes interesting reading. Not only does it incentivise work over welfare, it directly helps the lowest paid, and does so in a way that attaches social responsibility to business practices. The key detail is:

An increase in wages for everyone in the private sector to the level of the
"living wage" (£7.85 in London and £7.60 in the rest of the UK) would lead to an increase in gross earnings of between £11.4 billion and £12.0 billion, of which about £4.5 to £4.9billion would accrue to the Government through higher income tax and employee national insurance payments and lower spending on benefits and tax credits. Employers would also pay about £1.4 to £1.5 billion more in Employers’ National Insurance. In total, the Treasury would gain between £5.9 billion to £6.3 billion.
Dizzy had an interesting take on it yesterday morning re welfare reform. Note the calculation involves 'everyone in the private sector' including SME's paying a lot less in corporation tax (21%) than larger enterprises (28%), with little consequent scope for tax reductions. But this is just the type of initiative the treasury needs to be looking at.