起伏不定的石油行业，目前似乎正处于最新一轮颓势的早期阶段。
去年6月以来，原油价格暴跌了逾55％，降至每桶50美元（约合310元人民币）。这是自2009年经济衰退的低谷期以来油价的最低点。
石油业分析师纷纷预测，油价可能会跌破每桶40美元，然后反弹。不过，就连持乐观态度的人士也表示，年底之前很可能无法达到每桶70美元的价格。
为何油价会下降得如此之快？为何是现在？
这是个复杂的问题，但归根结底还是关于供需关系的简单经济学原理。
过去六年里，美国的石油产量几乎翻了一倍，于是原本出口美国的部分石油需要另寻出路。曾向美国出口的沙特阿拉伯、尼日利亚和阿尔及利亚的原油，突然开始争夺亚洲市场，使得出产国被迫降价。
从需求方面来看，欧洲和发展中国家的经济正在走弱，而机动车的能效也正在提高。因此，对燃料的需求稍显落后。
谁能从油价下跌中受益？
每个开机动车的人都可以告诉你，最近几个月，每加仑汽油的价格下跌了1美元多（约合每升1.64元）。柴油、取暖油和天然气的价格也出现大幅下滑。总体来看，这相当于一次规模不小的减税——在接下来的一年时间里，每个美国普通家庭的荷包里都会多出至少1000美元。欧洲和世界各地的消费者也将享受到类似的好处。
谁将蒙受损失？
首先是出产石油的国家和州。将面临经济——或许还有政治——动荡的石油国家，远远不止委内瑞拉、伊朗、尼日利亚、厄瓜多尔、巴西和俄罗斯。海湾国家很可能会缩小在世界各地的投资规模，或许还会削减对埃及等国的援助。
在美国，阿拉斯加、北达科他、得克萨斯、俄克拉荷马和路易斯安那将面临经济挑战。一些负债累累的规模较小的石油公司可能会倒闭，从而让贷款给它们的银行承压。
石油输出国组织遇到了什么情况？
就像其他大宗商品一样，石油的价格有升也有降。在过去，石油输出国组织（Organization of thePetroleum Exporting Countries，简称欧佩克）经常削减原油产量来稳定价格。伊朗、委内瑞拉和阿尔及利亚正在敦促该组织如法炮制，但沙特阿拉伯、阿拉伯联合酋长国及美国在海湾地区的其他盟国拒绝减产。与此同时，伊拉克实际上正在增加产量。
沙特官员表示，如果他们减产让油价回升，沙特就会失去市场份额，只能令竞争对手获益。
他们声称自己乐见油价继续深跌，但一些石油业分析师认为，这只是在虚张声势。
存在压低油价的阴谋吗？
当下阴谋论满天飞。就连一些石油公司高管都在私下里指出，沙特想要损害俄罗斯和伊朗的利益，美国也是如此——这样的理由足以让两个石油生产大国去压低油价。毕竟，20世纪80年代油价的不断下跌确实在一定程度上促成了苏联的解体。
然而，并没有证据来支持这些阴谋论，而且沙特阿拉伯和美国很少能够顺畅地相互配合。
除此之外，考虑到石油公司需追逐利润并要对股东负责，奥巴马政府实在难以协调数以百计的油企的石油开采工作。
油价何时可能反弹？
不会很快。美国及其他一些国家的石油产量仍在增加。很多华尔街投行预测，油价在未来几个月兴许会跌至每桶40美元。
不过，原油产量可能会在下半年开始减少，价格到时候也会开始反弹。在石油的发展史中，起起落落总是反复上演。（中国进出口网）
The oil industry, with its history of booms and busts, appears to be in the early stages of itslatest downturn.
The price of oil has plunged more than 55 percent to under $50 a barrel since June. That is thelowest price since the depths of the 2009 recession.
Oil analysts predict that the price could fall below $40 before beginning to rebound. But evenoptimists say $70 a barrel by the end of the year is highly doubtful.
Why is the price of oil dropping so fast? Why now?
This a complicated question, but it boils down to the simple economics of supply and demand.
United States domestic production has nearly doubled over the last six years, pushing out oilimports that need to find another home. Saudi, Nigerian and Algerian oil that once found ahome in the United States is suddenly competing for Asian markets, and the producers areforced to drop prices.
On the demand side, the economies of Europe and developing countries are weakening andvehicles are becoming more energy-efficient. So demand for fuel is lagging a bit.
Who benefits from the price drop?
Any motorist can tell you gasoline prices have dropped more than a dollar a gallon in recentmonths. Diesel, heating oil and natural gas prices have also fallen sharply. All together, theyrepresent the equivalent of a sizable tax cut — putting $1,000 or more in the pockets of theaverage family over the next year. Europeans and consumers around the world will enjoy similarbenefits.
Who loses?
For starters, oil-producing countries and states. Venezuela, Iran, Nigeria, Ecuador, Brazil andRussia are just a few petrostates that will suffer economic and perhaps even politicalturbulence. Persian Gulf states are likely to invest less money around the world, and may cutaid to countries like Egypt.
In the United States, Alaska, North Dakota, Texas, Oklahoma and Louisiana will face economicchallenges. Some smaller oil companies that are heavily in debt may go out of business,pressuring some banks that lend to them.
What happened to OPEC?
The price of oil, as with other commodities, goes up and down. And in the past the Organizationof the Petroleum Exporting Countries, known as OPEC, has frequently cut production to firm upprices. Iran, Venezuela and Algeria are pressing the cartel to do so again, but Saudi Arabia, theUnited Arab Emirates and other gulf allies are refusing to cut. At the same time, Iraq is actuallypumping more.
Saudi officials have said that if they cut production and prices go up, they will lose market shareand merely benefit their competitors.
They say they are willing to see oil prices go much lower, but some oil analysts think they aremerely bluffing.
Is there a conspiracy to bring the price of oil down?
There are a number of conspiracy theories floating around. Even some oil executives arequietly noting that the Saudis want to hurt Russia and Iran, and so does the United States —motivation enough for the two oil-producing nations to force down prices. Dropping oil prices inthe 1980s did help bring down the Soviet unio, after all.
But there is no evidence to support the conspiracy theories, and Saudi Arabia and the UnitedStates rarely coordinate smoothly.
And the Obama administration is hardly in a position to coordinate the drilling of hundreds ofoil companies seeking profits and answering to their shareholders.
When are oil prices likely to recover?
Not anytime soon. Oil production is still increasing in the United States and some othercountries. Many Wall Street banks are predicting that the oil price could fall as low as $40 abarrel in the coming months.
But production is likely to begin declining in the second half of the year, and then crude priceswill also begin to recover. The history of oil is a history of booms and busts followed by more ofthe same.
