外部性：计算产品的隐性成本Externalities: Calculating the Hidden Costs of Products
Nivi：什么是定价错误的外部性？你在上一期节目里提到过它。
Naval：外部性是指某种产品的生产或消费所带来的额外成本，而这部分成本没有计入产品的价格。这种情况可能由很多原因造成。有时你可以通过把成本重新计入价格来解决。
一些最激烈的资本主义批评者认为它正在摧毁环境。如果你因为资本主义破坏环境而把它抛弃，那么你猜怎么着——我们都会回到前工业时代。那可不是什么好事。
为外部性正确定价，比"感觉良好"的措施更有效
因为环境是有限而珍贵的，我们必须为它正确定价，并把价格重新计入产品和服务的成本中。
如果人们在浪费水、向大气排放碳氢化合物，或以其他方式污染环境，社会就应该向他们收取清理污染、让环境恢复原状所需的费用。也许这个价格必须非常、非常、非常高。
如果你把价格提高到足够高，就能消除污染。这比禁止塑料袋、干旱时限制淋浴之类的"感觉良好"的措施要好得多。
为外部性正确定价可以极大地节约资源
加州喜欢发布声明和广告，吓唬人们在干旱时不要淋浴。更好的做法是提高淡水的价格。普通消费者淋一次浴可能要多付几美分；但耗水量很大的杏仁种植户会减少用水，杏仁种植也可能会转移到国内水资源更丰富的地区。
为外部性正确定价可以极大地节约资源。当你想做诸如拯救环境这类事情时，这是一个好框架，而不是去做那些实际上不会产生任何效果的"感觉良好"的事情。
Nivi: What’s a mispriced externality? You mentioned it on a previous episode.
Naval: An externality is where there’s an additional cost imposed by whatever product is being produced or consumed, that’s not accounted for in the price of the product. This can happen for many reasons. Sometimes you can fix it by putting the cost back into the price.
Some of the most ardent critics of capitalism argue it’s destroying the environment. If you throw away capitalism because it’s destroying the environment, then guess what—we’re all headed back to pre-industrial times. That’s not going to be a good thing.
Pricing externalities properly is more effective than feel-good measures
Because the environment is finite and precious, we have to price it properly and fold that back into the cost of products and services.
If people are wasting water, releasing hydrocarbons into the atmosphere or polluting in other ways, society should charge them what it costs to clean up the pollution and return the environment to a pristine state. Perhaps that price has to be very, very, very high.
If you raise the price high enough, you’ll knock out pollution. That’s much better than feel-good measures like banning plastic bags or restricting showers during a drought.
Properly pricing externalities can save resources in a tremendous way
California likes to run declarations and ads to scare people into avoiding showers during droughts. It would be better to raise the price of fresh water. The average consumer might pay a few pennies more for a shower; but the almond farmers—who consume a lot of water—will cut back and almond farming may move to a part of the country where water is more abundant.
Properly pricing externalities can save resources in a tremendous way. It’s a good framework to use when you want to do things like save the environment, rather than doing feel-good things that won’t actually amount to anything.