Elroy Dimson

Well, when we first launched our research, we made some remarks about our predecessors' work.

That really illustrated some of the challenges that you faced.

So early on, we reported on the Premier Index Series for the UK.

That was prepared by a predecessor of Barclays Global Investors, who you know of, although they've also changed ownership.

That started with a stockbroking firm in the 1950s, hiring some general economists who weren't financial economists in those days to produce a long-term history.

And they wanted something which would represent the UK stock market.

The FT, the Financial Times Index, had begun in 1935, and they were going to go back further than 1935 to an earlier date.

They wanted their series to look similar to the standard FT series.

We wanted the pre-1935 data to be reflected with reference to the companies which were in the Financial Times Index after it launched.

So we had companies from 1934, 1933, 1932.

And as you went back in time, what the Barclays Global Investors Index or Barclays Capital Index contained was a set of companies that had done well enough to be big and it left out the companies that had died.

That index got replaced sometime after our own series came out.

But at the time, what we were doing was replacing an inadequate index with one that was adequate.

This is all ancient history, and I dare say Ross can live with that.

But if he wants me to rephrase anything, he'll tell me.

The term easy data bias is one that we coined.

The easiest state to collect is data which is readily accessible, which is well known.

The easy data that people had, including this data series for the UK, started after a period in which markets had become

unreliable, have less information behind them.

So, for example, the Barclays Index, which is still used by some people, it began life at the beginning of 1919.