“Finally, with respect to Thatcher, you seem to be shooting for something like my (3) above: the best ethos is the one that makes a nation richest.”
Her comment about that was that the Good Samaritan could not have helped the traveller and paid the innkeeper if he had no money no oil and no wine. Being rich is not an end in itself.

The ethos of the west was better because we didn’t have secret police, gulags, famines as a consequence of political doctrine, persecution of anyone who voiced disagreement with the government, etc. Yes that did have gradually increasing impacts on relative wealth, so the moral philosophy is a cause.
Most people would argue that the freedom of choice is a major reason for the superior economic performance of the west as different people would try different ideas and the most successful one would get widely adopted.

That is a complete Non sequitur. You might as well say eating junk food cannot be blamed for making me fat because I was already a couple of kilograms overweight before I started eating junk food.

The share of national wealth owned by the bottom half of the population has fallen by more than two-thirds under New Labour. [It fell by two-thirds in the first six years and has roughly halved again].
This is not just them getting a smaller share of growth – under New Labour the poor have actually got poorer.

You comment that it is difficult to get data on wealth – it is a very big coincidence that HMRC stopped publishing data and then withdrew data previously published after I made a fuss about the poor getting poorer while the rich got richer

Marketable wealth (excluding value of dwellings)
%age of wealth owned by 1976 1986 1996 1999 2000 2001 2002
Most wealthy 1% 29 25 26 34 33 34 37
Most wealthy 5% 47 46 49 59 59 58 62
Most wealthy 10% 57 58 63 72 73 72 74
Most wealthy 25% 73 75 81 87 89 88 87
Most wealthy 50% 88 89 94 97 98 98 98
Least wealthy 50% 12 11 6 3 2 2 2

HM Revenue and Customs

You might like to read Chris Giles’ article in today’s FT – no url for print version but if you don’t want to spend £2 you can read it in a public library. If you subscribe to ft.com you can find it but FT is fussy about copyright.
He says pay inequality has risen under New Labour, citing bankers but failing to mention MPs and senior civil servants.

Easily refutable, except it seems that you’re not going to throw us a usable citation or two. I perhaps should have been clearer to distinguish between ‘wealth’ and income’; even so, either way, I think the data supports my argument.

First, income inequality had its biggest increase in the 1980s, as this document from the National Statistics Office shows.

Information on wealth inequality is harder to come by, but this publication (from the Government Equalities Office) sets out some data (figure 2.20). I think a reasonable interpretation is that wealth inequality began to rise towards the end of the Thatcher administration and continued under Major into the New Labour years. There’s no data for 2004 onwards here.

However, the corollary to Cameron’s claim that New Labour’s policies are distinctive in having caused inequality is the claim that wealth inequality only began to rise under New Labour (after all, it’d be very odd to have an effect precede a cause). But the data doesn’t support this.

I think your marginal tax rate example is cherry picking.

Finally, with respect to Thatcher, you seem to be shooting for something like my (3) above: the best ethos is the one that makes a nation richest.

A little trick he seems to have picked up from American conservatives. The idea is to keep insisting that “money=size” until the corollary “less taxes=smaller government” becomes conventional wisdom. Then you can claim to be against big government while actually expanding the size and reach of government because, hey, you’ve cut taxes.