关注 | 新型冠状病毒在IB经济视角下的解读（一）

I'm sure you've seen a lot of biological articles about the existence of COVID-19.

我相信你们早就已经看过很多从生物学角度去分析新冠的存在的文章了。

But today you can re-understand this question from an economic perspective by reading this article.

但是今天，通过阅读本文，你们可以站在经济学的角度去寻找这个问题的答案。

As we all know, wild animals contains various viruses. As a result, those people who like to eat them may be terribly inflected and suffer from serious illnesses.

我们都知道，野生动物身上存在很多病毒。人们吃野生动物的行为会导致病毒感染，染上可怕的疾病。

Let's see how can one person's inflection because of eating wildlife affect both him/herself and the entire society：

让我们先来看看一个吃野味的人在被病毒感染后会怎样影响他/她自己和整个社会：

As we can see the virus caused by eating wildlife has negative influence on both individual and society.

我们可以看到吃野生动物产生的病毒对个人和社会都产生了不好的影响。

This is because the consumer and seller of wildlife gain much more benefits than the society!!!

这是因为买卖野生动物的人能够得到的好处远远多于这个社会所得到的！！！

This person derives pleasure from delicious taste of wildlife and the nutritional value that he thinks the wildlife has.

这个人通过野生动物的美味和他认为野生动物所含有的营养价值获得他个人的快乐。

Actually it tastes terrible and has virus instead of nutritional value.

事实上野生动物并不好吃，而且身上没有什么营养价值，病毒倒是很多。

We'll never know why he eats wildlife but anyway he gets pleasure by doing so O__O "…

我们可能永远无法理解为什么他要吃，不过吃野生动物确实让他感觉很开心O__O "…

In the introduction of the demerit goods, we found that the consumption of wildlife has a negative impact on the whole society.

在刚刚介绍有害品时，我们发现野味的消费对整个社会产生了负面的影响。

Besides, people who never eat wild animals, let alone gaining pleasure from eating, are inflected.

而且，有很多现在被感染的人从来没有吃过野生动物，更别说去享受吃野味的快乐了。

The consumers and sellers of wildlife ignore the negative externality.

野味的消费者和生产者忽略了负外部性。

However, the benefit that society can have from wildlife consumption has to contain both the personal pleasure of the consumer and the influence to third party.

然而，整个社会可以从野生动物的消费中所获得的好处需要包括野生动物消费者个人感受到的快乐和这个行为对第三方的影响。

This figure is the microeconomic model for wildlife market.

这幅图是野味市场的微观经济模型。

As we mentioned earlier, MSB=MPB+ negative externality

我们之前提到了，MSB=MPB+负外部性

we can do a simple calculation to derive this relationship: MSB<MPB .

我们可以做一个简单的计算。然后就可以得到这样一个关系：MSB<MPB

Therefore, in the figure, MPB curve is on the right side of the MSB curve.

因此，在图中，MPB线在MSB线的右侧。

The difference between MPB and MSB is the negative externality, which is represented by the green arrows in the diagram.

MPB和MSB之差就是负外部性，即图中用绿色箭头表示的部分。

In a market, there are people who consume wildlife, so there should be people who sell them.

在一个市场中，既然有买野味吃的人，必然会有卖野味的人。

 There are many buyers and sellers, which gradually forms a wildlife market.

有买有卖的就逐渐形成了一个野味市场

We just figured out why do people consume wildlife.

刚刚我们知道了为什么有人会去消费野味

Now let's see why people sell them.

那现在我们来看看为什么有人会去卖野味

According to one seller, the annual breeding cost of a civet is only 182 yuan, and the market price for the final product is 200 yuan per catty. This means a 3kg civet can bring thousands of yuan as net profits.

据卖家所说，一只果子狸一年的养殖成本仅需182元，成品的市场价为一斤200元。这意味着一只3公斤的果子狸成品出售的话，贩卖一只果子狸的净利润达到了近千元。

The huge profits of the illegal sale of the wildlife make the sellers become selfish, therefore ignore the consequences to the whole society, which results in the appearance of many similar markets.

非法贩卖野味的巨额利润使得卖家变得自私自利，不计其行为对整个社会的影响，因此产生了很多类似野味的市场。

According to the two intersections of the three lines (MSC, MSB, MPB) in the model, we can find the market price (Pm), the social optimal price (Popt), the market quantity (Qm) and the social optimal price (Qopt).

通过模型上的三条线（MSC、MSB、MPB）所相交的两个位置，我们可以对应找到市场价格（Pm）、社会分配最优价格（Popt）、市场数量（Qm）、社会分配最优数量（Qopt）。

we can also find the social welfare loss, that is, the blue area in the diagram.

我们也可以在图上找到社会福利损失（蓝色阴影部分）。

COVID-19 is first found in Wuhan seafood market where wildlife is illegally sold. Therefore, COVID-19 is also thought to have originated in wild animals.

今年的新型冠状病毒首先被发现在武汉的一个售卖野生动物的海鲜市场。而病毒也被认为是起源于这些被贩卖的野生动物。

We can say that economic transactions in the wildlife market caused the virus transmitted to the first person.

我们可以认为，野味市场的经济交易导致了这次的病毒首次传播到人的身上。

As of March 9, 2020, the total number of deaths due to coronavirus in China has reached 3124. Many of the 3124 are part of the working population, including some who have made great contributions to the society (such as doctors who died on duty). The country's labor and talent losses are a major manifestation of the negative impact of the above-mentioned wildlife trading.

截至2020年3月9日，中国由于新冠病毒累计死亡人数已达到3124人。这3124人里有许多是劳动人口，包括一些社会贡献很大的人（比如因公殉职的医生）。国家的劳动力和人才损失就是上述的交易野味带来的负面影响的一大体现。

From microeconomic perspective, COVID-19 and its impacts are all the negative externality of wildlife consumption!

从微观经济角度看，COVID-19以及病毒所带来的影响都是野味消费所产生的负外部性！

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