The last male group is treated differently because it has no raw weightings, and its relative weighting is contingent on the raw weightings for the other male groups.
Investors can beat the index by buying those stocks whose weightings can be expected to grow significantly, and by selling those whose weightings are likely to fall.
To keep their portfolios in line with their weightings, they have to buy shares when prices are rising and sell them when they are falling, amplifying volatility.So-called value investors are a further cause of instability.
Granted, risk weightings may never accurately reflect what's going on in the real world, but the newest proposal may fall into the same trap.
"A lot of managers are aware of the MSCI weightings, which dictate their own weightings," she said.
But we don't have London weightings on our wages".
Personal Capital favors an equal-weighting approach, where it creates stock portfolios with equal weightings of sectors.
Those weightings will then be adjusted every two years -- again in 2004, based on 2001-2002 surveys.
To measure weightings, Morningstar uses funds' most recent filings, which, of course, may be months old.
Investors, he said, should focus on the sector weightings of their entire portfolios, not individual funds.
