試驗教給我們的經驗:妙處無所不在大綱

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.

這裏有個小小的謎題。你得到了參加兩項高風險商業投資項目的機會。每個項目會花費你1.1萬英鎊。如果一切順利，每個項目將增值爲100萬英鎊。每個項目都只有1%的成功率。令人困惑的是，兩個項目的預期未來價值截然不同。

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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.

其中一個投資項目回報欠佳：你需要花費1.1萬英鎊才能獲得1萬英鎊的預期未來價值，也就是100萬英鎊的1%。除非你能從賭博中獲得巨大的樂趣，否則這種投資毫無道理。

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，另一個投資項目儘管也有風險，卻是絕佳的賭注。既然投資成本一樣，成功率也一樣，怎麼會這樣呢？

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.

其中的微妙差異是，這個具有吸引力的項目分成兩個階段。首先是試驗階段，成本爲1000英鎊。試驗失敗的機率是90%，一旦失敗，就會終止整個投資項目。如果試驗成功了，需要再投入1萬英鎊進行擴大投資，同時得到100萬英鎊未來價值的機率將爲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.

這種兩階段的投資方式改變了一切。即使總成本還是1.1萬英鎊，成功率還是1%，但能在試驗失敗後退出項目具有不可估量的價值。10次中有9次，試驗能讓你免於浪費1萬英鎊。這意味，採用一次性的投資方式將蒙受1000英鎊的預期損失，而採用兩階段的投資方式將得到8000英鎊的預期盈利。

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.

在真實的項目中，沒人能確定成功率或者回報究竟是多少。但這個例子背後的意義是千真萬確的：試驗有巨大的價值，它能幫助我們決定是該大幹一場，還是該退守陣地。

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”.)

我們可以從風險投資業的數據中看到這種效應。有一項研究考察了1986年到1997年間由美國風險資本家支持的企業，將這些企業與一組企業樣本相比較，樣本是從同行業中創建時長相同、規模相同的公司中隨機抽取的。（研究結果發表在今年夏天出版的《經濟展望期刊》(Journal of Economic Perspectives)上，文章標題爲《創業試驗》(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，僅有四分之一由風險資本家支持的企業存活了下來，而比照組中有三分之一的企業還在繼續經營。然而，前一類企業獲得了巨大的成功，員工數量是後一類企業的5倍多。我們無法從這個數據中推斷風險資本家到底是締造了成功還是僅僅提前預見了成功，但我們能從中發現，從總體上看，巨大的成功總是與極高的失敗率緊密相連。

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.

進行成本低廉的試運行非常有價值。我們很容易忽視這到底多麼有價值。在這一點上，火狐瀏覽器(Firefox browser)的首席設計師阿扎•拉斯金(Aza Raskin)引述了啓發了他的人物，已故的偉大航空工程師保羅•麥克雷迪(Paul MacCready)的事例。麥克雷迪最著名的成就是建造了兩架人力飛機“蟬翼神鷹”(Gossamer Condor)和“蟬翼信天翁”(Gossamer Albatross)。在20世紀70年代末，這兩架飛機打破了各項紀錄。

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.

麥克雷迪的關鍵理念之一是，建造一架能在墜機後迅速重建的飛機。他認爲，每一次試飛都能揭示新信息，但人力飛機重量太輕，每一次試飛都使飛機受損。設計者最重要的任務是建造一架在墜機後無需花費數週乃至數月時間，只需幾天甚至幾小時就能重建的飛機。一旦攻克瞭如何實現快速、低成本試驗的問題，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.

一些行業吸收了這個經驗。建築師用比例模型來表現完工的建築可能呈現出的外觀和質感。製作精巧的模型可能需要花費數天，但與建造實體建築的成本相比，這顯得微不足道。

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.”

政治人士發現這並不容易。除非一項新政策甫一推出就能大獲成功、備受讚賞，最好還能適時地讓人們感到驚訝，否則根本稱不上新政策。麥克雷迪的策略很難與之適配。想象一下這樣的會議致辭：“我們宣佈將就福利國家進行新一輪快速粗略的試驗。每次出現新的錯誤和令人心碎的小報軼聞後我們會迅速重新推出試驗。”

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

一個更微妙的問題是，只有項目達到一定規模，手握大權的決策者纔會認真對待這個項目。

“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.

“建立任何援助項目的交易成本太高，以至於絕大多數捐贈者不願意考慮任何支出少於2000萬英鎊的項目，”智庫全球發展中心(Center for Global Development)的歐洲主任歐文•巴德(Owen Barder)說。我懷疑，這一見解的適用範圍遠不止援助領域。因爲重要的利益相關者不想爲任何小事費心，政府和大企業可能會發現開展和運轉任何事務都是麻煩事。

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.

這太遺憾了。試驗項目的真正優勢是，儘管成本低廉，其結果的意義卻是巨大的。試驗本身似乎規模太小所以不值得費心，但試驗教給我們的經驗卻並非如此。