评论
打印
Why are gas stations always built right next to other gas stations?
为什么加油站总是建在其他加油站旁边？
Why is that I drive for a mile without finding a coffee shop and then stumble across three on the same corner?
为什么我们有时候会开了一英里却找不到一家咖啡店？然后突然发现有3家咖啡店在同一个拐角？
Why do grocery stores, auto repair shops and restaurants always seem to exist in groups instead of being spread evenly throughout a community?
为什么杂货店，汽车修理店和餐厅似乎总是聚在一起，而不是均匀地分布在整个区域？
While there are several factors that might go into deciding where to place your business, clusters of similar companies can be explained by a very simple story called Hotelling's Model of Spatial Competition.
虽然有多种因素可能会决定在哪里开店，但可以用一个简单的故事来解释为什么同类商店都聚在一起，这被称为霍特林模型空间竞争。
Imagine that you sell ice cream at the beach.
想象一下你在海滩上卖冰淇淋。
Your beach is one mile long and you have no competition.
海滩长达一英里并且没有任何竞争者。
Where would you place your cart in order to sell the most product?
你会把你的冰淇淋车放在哪里以卖出最多的产品？
In the middle.
在海滩中间。
The one-half-mile walk may be too far for some people at each end of the beach, but your cart serves as many people as possible.
对于在海滩两端的某些人来说，他们最多只用走半英里，但你的冰淇淋车却可以卖出最多的冰淇淋。
One day you show up at work just as your cousin Teddy is arriving at the beach with his own ice cream cart.
有一天你又来海滩卖冰淇淋，发现你的表兄弟泰迪带着他的冰淇淋车也在卖冰淇淋。
In fact, he's selling exactly the same type of ice cream as you are.
并且，他卖的冰淇淋和你的一模一样。
You agree that you will split the beach in half in order to ensure that customers don't have to walk too far you set up your cart a quarter mile south of the beach center, right in the middle of your territory.
为了让客户走的路程更短一些，你同意和他平分海滩。你把你的车放在距离海滩最南端1/4的地方，就在你地盘的中央。
Teddy sets up a quarter mile north of the center, in the middle of Teddy territory.
泰迪把它的冰淇淋车放在距离海滩北端1/4的地方，这是泰迪地盘的中央。
With this agreement, everyone south of you buys ice cream from you.
有了这个协议，在海滩南边这些人都会来你这里买冰淇淋。
Everyone north of Teddy buys from him, and the 50% of beachgoers in between walk to the closest cart.
在北边的那些人会从泰迪那里买冰淇淋。顾客都会去最近的冰淇淋车那里买。
No one walks more than a quarter of a mile, and both vendors sell to half of the beachgoers.
没有人会走1/4英里以上的路程，你们各自供应所有顾客所需冰淇淋的一半。
Game theorists consider this a socially optimal solution.
博弈论认为这是一个社会最优的解决方案。
It minimizes the maximum number of steps any visitor must take in order to reach an ice cream cart.
它把顾客为了走到冰淇淋车所需的最长路程给缩小了。
The next day, when you arrive at work, Teddy has set up his cart in the middle of the beach.
第二天你刚开始卖冰淇淋的时候发现泰迪把他的冰淇淋车放在了海滩的中间。
You return to your location a quarter mile south of center and get the 25% of customers to the south of you.
你回到了海滩南端的中间并且只得到了25%的顾客。
Teddy still gets all of the customers north in Teddy territory, but now you split the 25% of people in between the two carts.
泰迪仍然获得了他原先在海滩北端的顾客，但现在有25%的顾客处于两部冰淇淋车的中间。
