Subject: Re: Long term returns.
Have you analyzed the sources of Berkshire's outperformance? Here are just a few contributors:

1. Berkshire's equity portfolio, which makes up around half of IV, has outperformed the S&P by about 2 percentage points per year since 1996.
2. Float is about 29% of BV, which adds about 2 percentage points to the growth of BV and IV.
3. Berkshire's P/B has declined by about 1%/yr since 1996. The P/E on the S&P has increased by about 2%/yr.
4. Other contributors?

These are just rough numbers.