The Dow Jones index broke 12,000 points today for the first time since it opened in 1896. I saw a graph of the progress it had made (in today's Guardian), and the change was unmissable. For the first eight years or so its history it hardly broke 1,000. Between the 1960s and the 1980s it doubled in value in just twenty years. Then in the mid-80s, the Reagan/Thatcher era, it simply exploded and went into a massive upward climb. Not steadily upward of course; there was what, in the context of the times, was a major crash in 1987, but it had recovered in about five years.

Compare this to the 1929 crash, when the market lost about half its value, and it then took around another two decades for it to exceed its pre-1929 peak. The 1987 crash was also a picnic compared to the end of the boom of the 1990s, when the market fell from a high of almost 12,000 to 7,286. But despite losing almost half its' value, recovery this time around has been astonishingly rapid. It was only a couple of years before the 10,000 mark was passed again (though it was worth noting that there was a bad "bounce" along the way, when the marked dipped below 8,000 again on the way to recovery). And after only seven years, new records are being set.

Is it possible to conclude from this that the world economy is somehow more resilient than it used to be? Be that as it may, what is even more fascinating is where this new wealth has come from. In just 20 years, the market has created six times more wealth than it did in the previous eighty. This is, almost without a doubt, unprecedented in human history. It is, almost equally certainly, an unsustainable rate of increase; and there is, of course, no guarantee even that what we have now can be maintained. It is, nevertheless, fascinating to think about what the causes of this unique historical movement have been. Obviously, it coincides with the invention of the personal computer and the internet. But all sorts of financial inventions that I can't remotely claim to understand (such as the hedge fund and the rise of venture capital) have surely also been involved. And there must be many other factors involved. Note to self: must find a good modern economic history that explains all this stuff!