In Macedonia, a savings bank named TAT collapsed in 1997, erasing the economy of an entire major city, Bitola.

After much wrangling and recriminations - many politicians seem to have benefited from the scam - the government, faced with elections in September, has recently decided, in defiance of IMF diktats, to offer meager compensation to the afflicted savers. TAT was only one of a few similar cases. Similar scandals took place in Russia and Bulgaria in the 1990's .

One third of the impoverished population of Albania was cast into destitution by the collapse of a series of nation- wide leveraged investment plans in 1997. Inept political and financial crisis management led Albania to the verge of disintegration and a civil war. Rioters invaded police stations and army barracks and expropriated hundreds of thousands of weapons.

Islam forbids its adherents to charge interest on money lent - as does Judaism. To circumvent this onerous decree, entrepreneurs and religious figures in Egypt and in Pakistan established "Islamic banks". These institutions pay no interest on deposits, nor do they demand interest from borrowers. Instead, depositors are made partners in the banks' - largely fictitious - profits. Clients are charged for - no less fictitious - losses. A few Islamic banks were in the habit of offering vertiginously high "profits". They went the way of other, less pious, pyramid schemes.

They melted down and dragged economies and political establishments with them.

By definition, pyramid schemes are doomed to failure.

The number of new "investors" - and the new money they make available to the pyramid's organizers - is limited.

When the funds run out and the old investors can no longer be paid, panic ensues. In a classic "run on the bank", everyone attempts to draw his money simultaneously. Even healthy banks - a distant relative of pyramid schemes - cannot cope with such stampedes.

Some of the money is invested long-term, or lent. Few financial institutions keep more than 10 percent of their deposits in liquid on-call reserves.

Studies repeatedly demonstrated that investors in pyramid schemes realize their dubious nature and stand forewarned by the collapse of other contemporaneous scams. But they are swayed by recurrent promises that they could draw their money at will ("liquidity") and, in the meantime, receive alluring returns on it ("capital gains", "interest payments", "profits").