全球经济学家仍未解释清的五大经济谜团

最近，我获得了极为难得的机会，向四位曾在政府任职的顶尖经济学家请教当前经济中困扰我的五个问题。这四位经济学家分别是本•伯南克、迈克尔•波斯金、约瑟夫•斯蒂格利茨和莫里斯•奥布斯特菲尔德。他们受布鲁金斯学会哈钦斯中心主任大卫•韦塞尔邀请，参加了白宫经济顾问委员会成立70周年庆典。

我提出的五大谜以及四位经济学家的解答摘要如下：

生产率之谜：如果说出现了新的工业革命，那么生产率为何没有提高？

四位经济学家各抒己见，但总的来说，他们提出的原因包括统计数据不准，技术转化为生产率的提升存在滞后期，以及坦承物联网的意义或许不像电力那么重大。有人提到了罗伯特•戈登的新书《美国增长率的起伏》。我还没有拜读过。谁有时间看一本784页的书啊？

通胀之谜：失业率低于5%，为何没有看到通胀？反映失业率和通胀关系的菲利普斯曲线出了什么问题么？

伯南克说，用来表明失业与通货膨胀反向关系的菲利普斯曲线，可能仍是经济学家解读宏观经济的最佳框架。奥布斯特菲尔德则指出，对美国来说或许仍然适用，但就全球而言，失业率和通胀之间的关系已经不再遵从菲利普斯曲线。

油价之迷：油价下跌对经济来说为什么不是件好事？

痴迷于信息不对称理论的斯蒂格利茨说，价格大幅波动对经济的影响有好有坏，但看起来短期内不利影响将占据上风。

中国之迷：中国经济下滑会波及全球经济的其他领域吗？

四位经济学家都认为中国经济有问题，但伯南克态度乐观：“好消息是中国政府掌握着大量资源，而且愿意用来维持经济。”他还指出，中国的大多数债务都是国内债务，而不是外债，因此，中国经济即便出现问题也不会大范围传播。

贫富差距之迷：为何贫富差距越来越大？

不出所料，波斯金和斯蒂格利茨对此争执不下。波斯金的观点是全球贫富差距已经变小，发达国家的贫富差距主要源于技术和全球化，而且应该更关注经济普遍缺乏增长的问题，而不是贫富差距。斯蒂格利茨则引述了托马斯•皮凯蒂所著《21世纪的资本》中的观点。不过，这本696页的书我也没有读过。（财富中文网）

译者：Charlie

审校：夏林

Recently, I had the rare opportunity to quiz four of the smartest economists who have ever served in government – Ben Bernanke, Michael Boskin, Joseph Stiglitz and Maurice Obstfeld – on the five things that puzzle me about today’s economy. The panel was put together by David Wessel of the Hutchins Center at Brookings as part of a celebration of the 70th anniversary of the President’s Council of Economic Advisers.

My five mysteries, and some takeaways:

The productivity mystery: If we are in a new industrial revolution, why isn’t productivity growing?

Lively disagreement on this, but the answer seems to be a combination of bad statistics, long lags in achieving productivity gains from technology, and a recognition that the “internet of things” may not be as big as electricity. Some talk about Robert Gordon’s new book The Rise and Fall of American Growth, which I haven’t read. Who has time for 784 pages?

The inflation mystery: With unemployment below 5 percent, why isn’t there any? What happened to the “Philips Curve” relationship between unemployment and inflation?

Bernanke said the Philips Curve is probably still the best framework economists have to understand the macro economy. Obstfeld says that may be true in the U.S., but globally, the relationship has vanished.

The oil mystery: Why aren’t falling oil prices a good thing for the economy?

Stiglitz, who is fond of asymmetries, said big price movements have both good and bad economic effects, but the bad ones tend to win out in the short term.

The China mystery: Will its problems spill over into the rest of the global economy?

All agree China is a problem, but Bernanke played the optimist: “The good news is that the Chinese government has large resources and is willing to use them.” He also pointed out most Chinese debt is held inside the country, not overseas, limiting contagion.

The inequality mystery: Why is it getting worse?

Boskin and Stiglitz tussled over this one, as expected. Boskin’s argument: that global inequality has fallen; that inequality within developed countries is driven primarily by technology and globalization; and that it’s better to focus on lack of growth overall than on inequality. Stiglitz referred to Thomas Piketty’s book Capital in the Twenty-First Century which, at 696 pages, I also haven’t read.