As any pantomime-goer will tell you, the streets of London are paved with gold.
Some politicians will tell you that gold grows on trees across the English capital and is then handed on a plate to millionaire City bankers thanks to the collusion of London politicians in London-based parties, such as those well-known cockneys Gordon Brown and Alistair Darling.
A press release from Plaid Cymru MP Hywel Williams on the 2012 Olympics arrives today: "London politicians have admitted that it is a scam to use public money to regenerate one of Europe's richest cities."
He may have a point about Olympics spending not benefitting Wales, but is London really one of Europe's richest cities? It certainly contains some of Europe's richest people, but unemployment here is higher than in Wales (9.1 per cent compared to 8.6 per cent) and no fewer than 41 per cent of London's children are growing up in poverty after the UK capital's huge housing costs are considered.
The average price of a London property - £427,987 - may be more than twice as great as that of its Welsh equivalent - £161,576 - but Londoners still have to find a way to pay for their homes.
London's Evening Standard newspaper has just devoted a full week to an in-depth examination of the issue of poverty on its doorstep in a city home to some of the greatest inequalities you will find anywhere.
Incidentally, if, as Sir Jon Shortridge suggests, Wales is poor because it has been governed from England for too long, how do we explain economic fortunes in the poorest London boroughs?
London Mayor Boris Johnson gave a subdued (for him) interview to Dragon's Eye last week, warning against cutting spending in London, but it was enough to spark criticism from Plaid Cymru AM Chris Franks:
"These comments by Boris Johnson show that the Tories simply don’t care that Wales is being severely underfunded. They have consistently refused to say what they would do about our dire funding situation, and now it turns out they want to give more money to the richest region of England."
"London" is an easy label to prefix to any press release that aims to stoke up resentment among Welsh voters, particularly when included alongside "bankers" and other pantomime villains. It has subtly begun to replace "snub" and "slap in the face" in party propaganda.
Perhaps it's a delayed response to the former London Mayor Ken Livingstone's view of another major project (of questionable benefit to Wales): "We need Crossrail to keep London's economy ticking over so that we can continue to pay for the Scottish to live the lifestyle to which they are accustomed."
Statistics on London poverty may bore the pants off you if you live in Wales - probably if you live in London too - but they illustrate just how difficult it will be to reform the way the public spending cake is divided up.
David Cameron has been hinting of changes to the Barnett formula, which decides 53 per cent of public spending in Wales, for some time but always stops shy of promising action.
Two years ago, he told The Herald, Glasgow the formula was coming to the end of its days but he was wary of stoking an English grievance about it: "I want this to happen in a consensual, sensible, non-inflammatory way and that's why I've been so reticent about it."
For all the hints of commissions to look at it under a Tory government, he warned in last Friday's Western Mail that there was no pot of gold that would follow the scrapping of the formula.
Tweaking the formula to benefit Wales could deliver political benefits at relatively little financial cost for a Conservative UK government. The Tories could bite the bullet and cut Scottish spending disproportionately as soon as they take office, although that would not sit well with being a "party of the Union".
Lord Barnett is a sprightly 86. I wouldn't bet against him out-living his formula.