#Mark Hulbert: Have profit margins risen to a permanently high plateau?

The prospect of shrinking corporate profit margins has been scaring bulls for years now.

And, yet, those margins have stayed stubbornly high, thereby enabling the stock market to be surprisingly resilient. Earlier this month Wall Street received a mea culpa from the analyst who perhaps was the most outspoken champion of the shrinking margin hypothesis. He now believes profit margins may indefinitely stay above average. Even so, however, the stock market’s future prospects remain mediocre.

This…