Has the global economy entered an era of persistently high, volatile commodity prices? Our research shows that during the past eight years alone, they have undone the decline of the previous century, rising to levels not seen since the early 1900s (exhibit). In addition, volatility is now greater than at any time since the oil-shocked 1970s because commodity prices increasingly move in lockstep. Our analysis suggests that they will remain high and volatile for at least the next 20 years if current trends hold—barring a major macroeconomic shock—as global resource markets oscillate in response to surging global demand and inelastic supplies.