a diamond

一顆鑽石

or a bottle of water.

或一瓶水

It's an easy choice.

這很容易選擇

The diamonds are clearly more valuable.

鑽石顯然比較有價值

Now imagine being given the same choice again,

再想像一下，你現在面臨了同樣的選擇

only this time, you're not on a game show,

只是這次你不是在節目上

but dehydrated in the desert after wandering for days.

而是在沙漠裡遊蕩了幾天之後身體開始脫水

Do you choose differently?

你會做出不一樣的選擇嗎？

Why? Aren't diamonds still more valuable?

為什麼會不一樣？鑽石不是一樣比較有價值嗎？

This is the paradox of value,

這就是價值的悖論

famously described by pioneering economist Adam Smith.

著名的經濟學家先驅亞當‧斯密曾描述過此悖論

And what it tells us is that defining value is not as simple as it seems.

此悖論告訴我們的是，定義價值並不像表面上看起來那麼容易

On the game show, you were thinking about each item's exchange value,

在遊戲節目上，你想的是每個物品的交換價值

what you could obtain for them at a later time,

也就是過後你能用該物品換得其他物品的價值

but in an emergency, like the desert scenario,

但如同在沙漠中缺水等等的緊急狀況

what matters far more is their use value,

更為重要的是物品的使用價值

how helpful they are in your current situation.

也就是當前情況中物品對你有沒有幫助

And because we only get to choose one of the options,

而因為我們只能從兩樣東西中選出其中一樣

we also have to consider its opportunity cost,

我們還必須考慮到機會成本

or what we lose by giving up the other choice.

也就是放棄其他選擇的同時我們所失去的東西

After all, it doesn't matter how much you could get from selling the diamond

不管你能靠賣鑽石賺了多少錢，如果你沒辦法離開沙漠

if you never make it out of the desert.

那麼一切都不重要了

Most modern economists deal with the paradox of value

大部分現代經濟學家根據效用這個概念

by attempting to unify these considerations

試著統一各種考量

under the concept of utility,

來解決價值的悖論這個議題

how well something satisfies a person's wants or needs.

而效用即某物能滿足某人慾望或需求的程度

Utility can apply to anything from the basic need for food

效用可以應用在任何事物上，從最基本對食物的需求

to the pleasure of hearing a favorite song,

到聽最愛的歌時獲得的愉悅感

and will naturally vary for different people and circumstances.

而效用也會因不同人、不同情況而隨之改變

A market economy provides us with an easy way to track utility.

市場經濟提供了一個容易觀察效用的方法

Put simply, the utility something has to you

簡單來說，你能獲得多少效用

is reflected by how much you'd be willing to pay for it.

反映在你願意為了效用付出多少代價

Now, imagine yourself back in the desert,

現在想像一下你回到了沙漠中

only this time, you get offered a new diamond or a fresh bottle of water

只是這次，你每五分鐘會得到新的鑽石

every five minutes.

或新的一瓶水

If you're like most people, you'll first choose enough water to last the trip,

如果你跟大多數人一樣，你會選擇先獲得足夠的水來繼續旅程

and then as many diamonds as you can carry.

接著再依你能帶的量，把鑽石帶走

This is because of something called marginal utility,

會做這樣的抉擇是因為邊際效用的緣故

and it means that when you choose between diamonds and water,

邊際效用是指，在鑽石和水之間做選擇時

you compare utility obtained from every additional bottle of water

你會把每增加一瓶水所獲得的效用

to every additional diamond.

與每增加一顆鑽石所獲得的效用相互比較

And you do this each time an offer is made.

每當做選擇時你都會做一次比較

The first bottle of water is worth more to you than any amount of diamonds,

對你來說，再多的鑽石都不比第一瓶水來的有價值

but eventually, you have all the water you need.

但到了最後你有了足夠的水

After a while, every additional bottle becomes a burden.

再過一陣子，每多一瓶水都是負擔

That's when you begin to choose diamonds over water.

這時你就會開始捨棄水而選擇鑽石

And it's not just necessities like water.

不只是像水這樣的必需品

When it comes to most things, the more of it you acquire,

大部分的東西，你獲得愈多

the less useful or enjoyable every additional bit becomes.

東西就會變得愈不實用、不有趣

This is the law of diminishing marginal utility.

這就是邊際效用遞減法則

You might gladly buy two or three helpings of your favorite food,

你買兩三份最愛的食物應該會很開心

but the fourth would make you nauseated,

但第四份就會讓你覺得噁心

and the hundredth would spoil before you could even get to it.

到了第一百個時你還沒吃到食物就會腐壞了

Or you could pay to see the same movie over and over until you got bored of it

你也可以一再地看同一部電影，看到你覺得無聊

or spent all of your money.

或看到花光你的錢為止

Either way, you'd eventually reach a point

不管怎樣，最後都會達到一個點

where the marginal utility for buying another movie ticket became zero.

在這個點上，買電影票的邊際效用變成零

Utility applies not just to buying things, but to all our decisions.

效用不只應用在買東西上，也適用在我們做的所有決定

And the intuitive way to maximize it and avoid diminishing returns

最直接能最大化效用，並避免產生報酬遞減的方法

is to vary the way we spend our time and resources.

就是改變我們花費時間、資源的方式

After our basic needs are met,

我們的基本需求滿足了之後

we'd theoretically decide to invest in choices

理論上會決定投資在

only to the point they're useful or enjoyable.

所選擇的事物是有用的、有趣的那一點上

Of course, how effectively any of us manage to maximize utility in real life

當然，現實生活中我們如何有效地最大化效用

is another matter.

又是另外一回事了

But it helps to remember that the ultimate source of value comes from us,

但這件事能提醒我們，價值最根本的源頭來自於我們

the needs we share,

來自我們共享的需求

the things we enjoy,

我們享受的事物

and the choices we make.

以及我們所做的選擇