But, of course, hindsight is 20 20.

And of course the hindsight bias is perfect.

We cannot afford to have to say in hindsight that the global response to the tsunami of December 2004 was business as usual.

Hindsight suggests that the authorities should have done just that. Faced with foreign opposition, the government should have announced its decision to restructure as a fait accompli.

As to whether the demonstrations were doomed to end in failure and bloodshed, this too is easy to say in hindsight. History may never repeat itself precisely, but certain patterns can be discerned.

Americans have been through this type of debate before. Twenty years ago, we were gripped by fear that Japan would overtake our economic leadership a concern that was unfounded then and, in hindsight, looks profoundly mistaken.

It is held culpable for the near financial meltdown. But 30 years of hindsight enable us to judge which elements of the Thatcher revolution should be preserved, and which should be amended in the light of today s global economic downturn.

There are no heroes in this story, certainly not Argentina s policymakers, who a decade ago attempted unilaterally to force a massive generalized write down on foreign bondholders. Economists who trumpeted the Buenos Aires consensus as the new way to run economies also look foolish in hindsight.

Rogoff argues that while, in hindsight, the government should have borrowed more, at the time there was a real danger that Britain would go the way of Greece. So Chancellor of the Exchequer George Osborne turns out, on this view, to be a hero of global finance.

In China, changes in the export sector s structure similar to those observed in Japan are now taking place. These changes are likely to make today s attempts to find an equilibrium yuan dollar exchange rate seem just as chimerical in hindsight as previous calculations of the yen dollar equilibrium rate.

The UN Special Rapporteur on the Right to Education, in her discussion about the purpose of education, asks if it is reinforcing or eliminating inequality. She states (Tomaševski 2004, paras 29 30) that it is easy, with hindsight, to highlight the main features of collapsed models of schooling .

So the headlines proclaim Einstein was right after all, as though scientists should be compared as one would clairvoyants Who is distinguished from the common herd by knowing the unknowable such as the outcome of experiments that have yet to be conceived, let alone conducted? Who, with hindsight, has prophesied correctly?

For example, the classic 1972 bestseller Limits to Growth predicted that the world would run out of gold in 1981, silver and mercury in 1985, and zinc in 1990. We have the benefit of hindsight today, but even now most discussions of the issue are predicated on the logic of Limits to Growth .

With hindsight, one can identify other deficiencies in the euro of which its architects were unaware. The euro was supposed to bring about economic convergence, but it produced divergences instead, because its architects did not realize that imbalances may emerge not only in the public sector, but in the private sector as well.

With hindsight, it has become clear that there was in fact no coherent growth story for most emerging markets. Scratch the surface, and you found high growth rates driven not by productive transformation but by domestic demand, in turn fueled by temporary commodity booms and unsustainable levels of public or, more often, private borrowing.

The third point is more diagnostic The shockingly anemic pattern of post crisis US consumer demand has resulted from a deep Japan like balance sheet recession. With the benefit of hindsight, we now know that the 12 year pre crisis US consumer spending binge was built on a precarious foundation of asset and credit bubbles.

In hindsight, it was a mistake to believe in the euro s spontaneous community creating power. Though there clearly is a link between currency areas and political communities (consider the dissolution of the ruble zone at the time of the Soviet Union s collapse), it is political community that creates the solidarity needed to foster currency linkages, not vice versa.

With 20 20 hindsight, it is clear that in 1997 98, weak bank regulation and corporate governance aggravated the depth of the economic contraction that followed the sudden stop of capital flows. But what exactly does this imply for how middle and low income countries today should set their capital account policies amid the current flood?