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)。）