By Steve Schifferes
Economics reporter, BBC News
Government bank bail-outs have been controversial in the US
The global credit crunch has cost governments more than $10 trillion, the International Monetary Fund (IMF) says.
The IMF says that rich countries have provided $9.2tn in government support for the financial sector, while emerging economies spent $1.6 tn.
About $1.9tn represents up-front expenditure, while the rest is made up of guarantees and loans.
Governments are likely to recover most of these sums when the world economy recovers, but big deficits will stay.
The financial bail-out costs include:
- Capital injections: $1.1tn
- Purchase of assets: $1.9tn
- Guarantees: $4.6tn
- Liquidity provision: $2.5tn
The IMF has also been revising its estimates of the cost of the global downturn on government budgets.
It now says that overall, the rich countries of the G20 group will suffer a budget deficit of 10.2% of economic output or gross domestic product (GDP) in 2009, the largest for most countries since World War II.
The largest projected budget deficits are in the US, with 13.5% of GDP, the UK, with 11.6%, and Japan 10.3%.
However, the UK will have the largest projected budget deficit of all G20 countries by 2010, at 13.3% of GDP, compared to 9.7% for the US.
The rising budget deficits have been caused by a combination of the severe global economic downturn, which has slashed government revenues, and the stimulus measures introduced by some governments to try and kick-start the recovery.
The IMF estimates that the G20 countries will implement stimulus plans worth 2% of their GDP in 2009, and 1.6% in 2010 - but it says it is difficult to measure how effectively these have actually been implemented.
However, it says that such plans have had a big effect on limiting the severity of the recession.
It estimates that such spending has boosted growth in G20 countries by between 1.2% and 4.7% this year.
The IMF says increased spending is more effective than cutting taxes in boosting demand, and works best when implemented in conjunction with looser monetary policy and in a coordinated fashion around the world.
The IMF estimates - prepared ahead of the G20 summit of world leaders in Pittsburgh in September - also show how much long-term damage the crisis is doing to public finances.
It estimates that by 2014, government debt will reach 239% of GDP in Japan, 132% in Italy, 112% in the US, and 99.7% in the UK.
Proportionately, however, the rise in the UK is the biggest - with debt more than doubling from 44% in 2007.
Rating agencies have recently warned that a UK debt of 100% of GDP would force them to consider downgrading the credit rating of UK government bonds.
This could make it more costly for the government to raise money.
The IMF says that it is important for governments to show a credible path for reducing deficits in the long-run, although it urges them to continue the fiscal stimulus in the short-term.
A "lack of policy credibility (either real or perceived)" makes fiscal expansion less effective by raising risk and raising real interest rates.
G20 leaders are set to discuss the state of the world economy at their next summit in September, and look at the effectiveness of measures to revive the economy and regulate the banking sector.