试验教给我们的经验:妙处无所不在

Here’s a little puzzle. You’re offered the chance to participate in two high-risk business ventures. Each costs £11,000. Each will be worth £1m if all goes well. Each has just a 1 per cent chance of success. The mystery is that the ventures have very different expected pay-offs.

这里有个小小的谜题。你得到了参加两项高风险商业投资项目的机会。每个项目会花费你1.1万英镑。如果一切顺利，每个项目将增值为100万英镑。每个项目都只有1%的成功率。令人困惑的是，两个项目的预期未来价值截然不同。

One of these opportunities is a poor investment: it costs £11,000 to get an expected payout of £10,000, which is 1 per cent of a million. Unless you take enormous pleasure in gambling, the venture makes no sense.

其中一个投资项目回报欠佳：你需要花费1.1万英镑才能获得1万英镑的预期未来价值，也就是100万英镑的1%。除非你能从赌博中获得巨大的乐趣，否则这种投资毫无道理。

Strangely, the other opportunity, while still risky, is an excellent bet. With the same cost and the same chance of success, how could that be?

奇怪的是，另一个投资项目尽管也有风险，却是绝佳的赌注。既然投资成本一样，成功率也一样，怎么会这样呢？

Here’s the subtle difference. This attractive alternative project has two stages. The first is a pilot, costing £1,000. The pilot has a 90 per cent chance of failing, which would end the whole project. If the pilot succeeds, scaling up will cost a further £10,000, and there will be a 10 per cent chance of a million-pound payday.

其中的微妙差异是，这个具有吸引力的项目分成两个阶段。首先是试验阶段，成本为1000英镑。试验失败的几率是90%，一旦失败，就会终止整个投资项目。如果试验成功了，需要再投入1万英镑进行扩大投资，同时得到100万英镑未来价值的几率将为10%。

This two-stage structure changes everything. While the total cost is still £11,000 and the chance of success is still 1 per cent, the option to get out after a failed pilot is invaluable. Nine times out of 10, the pilot will save you from wasting £10,000 – which means that while the simple project offers an expected loss of £1,000, the two-stage project has an expected profit of £8,000.

这种两阶段的投资方式改变了一切。即使总成本还是1.1万英镑，成功率还是1%，但能在试验失败后退出项目具有不可估量的价值。10次中有9次，试验能让你免于浪费1万英镑。这意味，采用一次性的投资方式将蒙受1000英镑的预期损失，而采用两阶段的投资方式将得到8000英镑的预期盈利。

In a real project, nobody could ever be sure about the probability of success or its rewards. But the idea behind this example is very real: there’s huge value in experiments that help us decide whether to go big or go home.

在真实的项目中，没人能确定成功率或者回报究竟是多少。但这个例子背后的意义是千真万确的：试验有巨大的价值，它能帮助我们决定是该大干一场，还是该退守阵地。

We can see this effect in data from the venture capital industry. One study looked at companies backed by US venture capitalists (VCs) between 1986 and 1997, comparing them with a sample of companies chosen randomly to be the same age, size and from the same industry. (These results were published in this summer’s Journal of Economic Perspectives in an article titled “Entrepreneurship as Experimentation”.)

我们可以从风险投资业的数据中看到这种效应。有一项研究考察了1986年到1997年间由美国风险资本家支持的企业，将这些企业与一组企业样本相比较，样本是从同行业中创建时长相同、规模相同的公司中随机抽取的。（研究结果发表在今年夏天出版的《经济展望期刊》(Journal of Economic Perspectives)上，文章标题为《创业试验》(Entrepreneurship as Experimentation)。）

By 2007, only a quarter of the VC-backed firms had survived, while one-third of the comparison group was still in business. However, the surviving VC-backed firms were big successes, employing more than five times as many people as the surviving comparison firms. We can’t tell from this data whether the VCs are creating winners or merely spotting them in advance but we can see that big successes on an aggregate scale are entwined with a very high failure rate.

到2007年，仅有四分之一由风险资本家支持的企业存活了下来，而比照组中有三分之一的企业还在继续经营。然而，前一类企业获得了巨大的成功，员工数量是后一类企业的5倍多。我们无法从这个数据中推断风险资本家到底是缔造了成功还是仅仅提前预见了成功，但我们能从中发现，从总体上看，巨大的成功总是与极高的失败率紧密相连。

The option to conduct a cheap test run can be very valuable. It’s easy to lose sight of quite how valuable. Aza Raskin, who was lead designer for the Firefox browser, cites the late Paul MacCready as his inspiration on this point. MacCready was one of the great aeronautical engineers, and his most famous achievement was to build the Gossamer Condor and the Gossamer Albatross, human-powered planes that tore up the record books in the late 1970s.

进行成本低廉的试运行非常有价值。我们很容易忽视这到底多么有价值。在这一点上，火狐浏览器(Firefox browser)的首席设计师阿扎•拉斯金(Aza Raskin)引述了启发了他的人物，已故的伟大航空工程师保罗•麦克雷迪(Paul MacCready)的事例。麦克雷迪最著名的成就是建造了两架人力飞机“蝉翼神鹰”(Gossamer Condor)和“蝉翼信天翁”(Gossamer Albatross)。在20世纪70年代末，这两架飞机打破了各项纪录。

One of MacCready’s key ideas was to develop a plane that could swiftly be rebuilt after a crash. Each test flight revealed fresh information, MacCready figured, but human-powered planes are so feather-light that each test flight also damages the plane. The most important thing a designer could do was to build a plane that could be rebuilt within days or even hours after a crash – rather than weeks or months. Once the problem of fast, cheap experimentation was solved, everything else followed.

麦克雷迪的关键理念之一是，建造一架能在坠机后迅速重建的飞机。他认为，每一次试飞都能揭示新信息，但人力飞机重量太轻，每一次试飞都使飞机受损。设计者最重要的任务是建造一架在坠机后无需花费数周乃至数月时间，只需几天甚至几小时就能重建的飞机。一旦攻克了如何实现快速、低成本试验的问题，其他的事情就迎刃而解了。

Some professions have internalised this lesson. Architects use scale models to shed light on how a completed building might look and feel. A nicely made model can take days of work to complete but that is not much compared with the cost of the building itself.

一些行业吸收了这个经验。建筑师用比例模型来表现完工的建筑可能呈现出的外观和质感。制作精巧的模型可能需要花费数天，但与建造实体建筑的成本相比，这显得微不足道。

Politicians don’t find it so easy. A new policy is hardly a new policy at all unless it can be unveiled in a blaze of glory, preferably as a well-timed surprise. That hardly suits the MacCready approach. Imagine the conference speech: “We’re announcing a new array of quick-and-dirty experiments with the welfare state. We’ll be iterating rapidly after each new blunder and heart-rending tabloid anecdote.”

政治人士发现这并不容易。除非一项新政策甫一推出就能大获成功、备受赞赏，最好还能适时地让人们感到惊讶，否则根本称不上新政策。麦克雷迪的策略很难与之适配。想象一下这样的会议致辞：“我们宣布将就福利国家进行新一轮快速粗略的试验。每次出现新的错误和令人心碎的小报轶闻后我们会迅速重新推出试验。”

A subtler problem is that projects need a certain scale before powerful decision makers will take them seriously.

一个更微妙的问题是，只有项目达到一定规模，手握大权的决策者才会认真对待这个项目。

“The transaction costs involved in setting up any aid project are so great that most donors don’t want to consider a project spending less than £20m,” says Owen Barder, director for Europe at the Center for Global Development, a think-tank. I suspect that the same insight applies far beyond the aid industry. Governments and large corporations can find it’s such a hassle to get anything up and running that the big stakeholders don’t want to be bothered with anything small.

“建立任何援助项目的交易成本太高，以至于绝大多数捐赠者不愿意考虑任何支出少于2000万英镑的项目，”智库全球发展中心(Center for Global Development)的欧洲主任欧文•巴德(Owen Barder)说。我怀疑，这一见解的适用范围远不止援助领域。因为重要的利益相关者不想为任何小事费心，政府和大企业可能会发现开展和运转任何事务都是麻烦事。

That is a shame. The real leverage of a pilot scheme is that although it is cheap, it could have much larger consequences. The experiment itself may seem too small to bother with; the lesson it teaches is not.

这太遗憾了。试验项目的真正优势是，尽管成本低廉，其结果的意义却是巨大的。试验本身似乎规模太小所以不值得费心，但试验教给我们的经验却并非如此。