By regional analyst Nicholas Nugent
In early 2000, the World Bank estimated that corruption was costing the Philippines government $47m a year - or a massive $48 bn over the 20-year period to 1997.
Corruption, said the hard-hitting World Bank report, undermines development, hurts the poor, diminishes the quality of public services and raises the price of goods and services.
The report said private industry shared a responsibility for this state of affairs by its attempts to bribe politicians.
There have been a lot of allegations against me these days and I would like to know who these alligators are
Though the report covered a period before Mr Estrada became president, the former film star turned businessman has himself been named in a number of corruption scandals since entering politics.
He has been accused of blurring the line between business and politics, and bringing the high office of the presidency into disrepute.
Businesses and mistresses
Newspaper reports say he and his close family have interests in up to 68 companies, 11 of them set up since he became president.
Suggesting that such business activity left him little time to take his political responsibilities seriously, the reports accused him of using the power of patronage to benefit his friends and business associates.
Estrada has been open about his closeness to some tycoons
Vote-buying and rewards
But the fact that Mr Estrada so openly admits much of what is alleged about his business and personal life demonstrates the extent to which political patronage of business is widely accepted.
Traditionally, government contracts and appointments are used to buy votes and to reward campaign funding and loyalty.
The press have been critical of Mr Estrada's business links
Mr Estrada makes no secret of his closeness to business
tycoons like Lucio Tan of Philippine Airlines and plastics tycoon William Gatchalian, whose financial contributions to his election victory were rewarded with sinecures.
According to a report by the Philippines Centre for Investigative Journalism, about 2% of state employees - about 6000 individuals - were presidential appointees.
They included posts in education and social security as well as senior armed forces officers and employees of two state banks.
The report suggests he used his power of appointment to advance his business interests.
Referring to the president's openness about his use of patronage, the report asks: "How do you deal with a sinner who confesses to his sins with devastating nonchalance?"
Some senior army officers were found to be presidential appointees
In pushing for the president's impeachment his opponents believed they were furthering a process of political reform begun 14 years ago - when former President Ferdinand Marcos was forced to step after being accused of "fixing" election results in his favour, as well as using his position to enrich himself.