When they try to persuade investors, and often themselves, that synergies abound (that two and two equals not merely five but six or more) in their takeovers of firms engaged in activities that they know next to nothing about, companies prefer such euphemisms as multi-industry business or non-related diversification.

ECONOMIST: Bidder beware | The

This second rule challenges the conventional wisdom that the safest diversification is into an industry closely related to your own: after several years and a great deal of research, Mr Broad built his second Fortune 500 firm in an entirely unrelated business: financial products for retirement.

ECONOMIST: Uncommonly unreasonable

On the domestic front, the Arab Spring-related spending is accelerating a longer-term shift toward economic diversification through domestic projects that include aluminum smelters in Saudi Arabia and the U.A.E.

WSJ: Gulf Countries Splurge at Home

Further, Toussaint related, portfolio managers might also be looking at the difference between gold and other commodities for diversification.

FORBES: WGC's Toussaint: China, India Account More Than Half Of Global Gold Demand