As the global downturn continues, the world economy faces a period of lower oil prices and overall demand for energy, a welcome change for consumers after the price spikes of recent years. But unless policy makers can find ways to improve the balance between energy supply and demand, the current slackness in energy markets will last no longer than it takes for the global economy to recover. That scenario will eventually impose significant costs on consumers and businesses in the form of higher energy prices. The importance of achieving a supply–demand balance extends, of course, beyond the next few years: in the longer term, demand seems set for robust growth.

As of late April 2009, the price of oil stood at around $50 a barrel—down from a high of nearly $150 a barrel in July 2008, though many observers doubt that oil demand will rebound enough after the current economic downturn to prompt another price shock. However, research from the McKinsey Global Institute conducted in 2008 and 2009 reveals the potential for a new spike in the price of oil between 2010 and 2013. Exactly when this potential spike will occur—or if overall demand for energy will reach levels significantly...