Some weeks ago I wrote a blog b-index – ett nytt sätt att utvärdera fonder och fondförvaltare! about an idea, the b-index, I have about evaluating funds and fund managers in a novel way. The index is based on the Hirsch index, also called the h-index, used in ranking the research output of scientists.
Now, in this entry I would like to do two things: (i) briefly explain my idea in English (the old entry was in Swedish), and (ii) explain the whole idea again (I have got several questions and since the idea is dead simple I must have done a bad job explaining it).
Anyway, my idea is thoroughly described in my article An Index to Evaluate Fund- and Fund Manager Performance (scroll down to the section called Working Papers where you can find the paper) and the whole point is that the b-index summarizes the performance of a fund or fund manager in a simple and, dare I say, quite elegant way. I do not claim that it is the best measure ever conceived but I do claim that it is OK (and simple/elegant). The main idea is that the b-index summarizes the performance in one single number, that is the value b. And this value, called the b-index, is defined as follows:
A fund or fund manager has a b-index equal to b if b is the highest number for which it holds that the fund/fund manager has returned more than b% at least b years throughout the history of the fund/fund manager.
OK, perhaps it is a stupid idea, but I do not understand why (this possibly stupid idea) is so difficult to understand! If necessary, the b-index, as defined above, can be complemented with an identical index for negative investment returns (losses). A combination of the two indexes (b+ and b-) would then add a risk-dimension to the performance evaluation. Moreover, the b- -index can of course be interpreted as an alternative risk measure if used on its own.
I find the b-index to be a viable alternative to a range of other natural, simple and widely used performance measure such as the average annual historical return or the historical cumulative return. In the paper I present some actual b-indexes (b+ as well as b-) for a range of well-known funds and fund managers, for instance my old hero Warren Buffett! He has a very respectable b-index equal to 16: over the last 33 years he has produced 16 years with an annual return above 16% (and one single year with more than 1% loss, i.e. a negative b- -index = 1)! Try to beat that!!!!