http://www.foreignaffairs.com/articles/141218/tyler-cowen/capital-punishment

"It is also worth noting that many wealth accumulators never fully diversify their holdings, or even come close to doing so. Gates, for example, still owns a lot of Microsoft stock -- perhaps out of a desire for control, or because of a sentimental attachment to the company he co-founded, or maybe just due to excessive optimism. Whatever the reasons, over time such concentrations of financial interest hasten the circulation of elites by making it possible for the wealthy to suffer large losses very rapidly.

And in the end, even the most successful companies will someday fall, and the fortunes associated with them will dissipate. In the very long run, the most significant gains will be reaped by institutions that are forward-looking and rational enough to fully diversify. As Piketty discusses, that category includes the major private U.S. universities, and indeed the list of the top schools has not changed much over many decades. Harvard and other elite universities might, in fact, emerge as the true rentiers of the contemporary era: as of 2008, the top 800 U.S. colleges and universities controlled almost $400 billion in assets."

(http://www.autoadmit.com/thread.php?thread_id=2572073&forum_id=2#25627844)

(http://www.autoadmit.com/thread.php?thread_id=2572073&forum_id=2#25835102)