Seeking Alpha has an article by a Berkshire Hathaway shareholder about the Warren Buffett-run company's tax situation:
One idea that struck me recently is that ever since the Bush capital gains tax cuts were passed, Berkshire immediately became a less attractive investment opportunity for one reason: it's extremely tax-inefficient. Despite its tremendous move towards buying operating businesses instead of shares in publicly traded companies over the past decade, a significant percentage of Berkshire's book value still rests with its equity portfolio. After the Bush tax cuts, even investors in the highest income bracket pay only 15% capital gains tax. Meanwhile, Berkshire still has to pay the standard 35% corporate tax on any realized gains. Talk about a drag on performance! Buffett has always criticized hedge funds for being unable to outperform their benchmarks after charging their clients exorbitant fees, but Berkshire investments carry the biggest fee of all: corporate taxes.
If the article is correct about that, it's interesting, because Mr. Buffett has been campaigning to lower corporate tax rates and increase capital gains tax rates.