Originally Posted by my previous link
The recent authors, notably Campbell and Laherrere have apparently rediscovered the Hubbert curve, but without understanding it, at least initially. Campbell and Laherrere initially argued that production should follow a bell curve, at least in an unconstrained province. But this is demonstratively not the case in practice: most nations’ production does not follow a Hubbert curve. In fact, Campbell (2003) shows production curves (historical and forecast) for 51 non-OPEC countries, and only 8 of them could be said to resemble a Hubbert curve even approximately.
The authors initially responded to this weakness by arguing that the Hubbert curve could have multiple peaks, which of course means it would not follow a bell curve at all, and destroys the explanatory value of the bell curve.