"We found long-term investors, who are not just looking at the short-term returns typical of private equity," Wiesenthal said.

Standard deviation shows the range in which the short-term returns vary from the long-term average.

They generally do not expect a short-term return.

But keeping a clear focus on the long-term nature of investing is important to avoid being blinded by eye-popping short-term returns.

"All serious long-term investors must accept the risk of lower short-term returns to achieve high long-term results," he said in a statement.

It is also true that those willing to take risks may get good short-term returns in the secondary market.

Or, they can pursue solutions to the crisis in ways that go beyond just the typical calculations of short-term returns.

District heating is a long-term commitment that fits poorly with a focus on short-term returns on investment.

Today there's such a focus on the short-term return, on that quarterly stock report.

But behind all this are foreign- exchange traders, constantly in search of the greatest short-term return on their holdings.