Especulação?

Um artigo de Paul Krugman sobre se a subida do preço do petróleo é devida a especulação (via Economist's View):

So here are two questions: Are speculators mainly, or even largely, responsible for high oil prices? And if they aren’t, why have so many commentators insisted, year after year, that there’s an oil bubble?

Now, speculators do sometimes push commodity prices far above the level justified by fundamentals. But when that happens, there are telltale signs that just aren’t there in today’s oil market.

Imagine what would happen if the oil market were humming along, with supply and demand balanced at a price of $25 a barrel, and a bunch of speculators came in and drove the price up to $100.

Even if this were purely a financial play on the part of the speculators, it would have major consequences in the material world. Faced with higher prices, drivers would cut back on their driving; homeowners would turn down their thermostats; owners of marginal oil wells would put them back into production.

As a result, the initial balance between supply and demand would be broken, replaced with a situation in which supply exceeded demand. This excess supply would, in turn, drive prices back down again — unless someone were willing to buy up the excess and take it off the market.

The only way speculation can have a persistent effect on oil prices, then, is if it leads to physical hoarding — an increase in private inventories of black gunk. This actually happened in the late 1970s, when the effects of disrupted Iranian supply were amplified by widespread panic stockpiling.

But it hasn’t happened this time: all through the period of the alleged bubble, inventories have remained at more or less normal levels. This tells us that the rise in oil prices isn’t the result of runaway speculation; it’s the result of fundamental factors, mainly the growing difficulty of finding oil and the rapid growth of emerging economies like China.