The Hierarchy of Demands 需求的层级

Source: https://book.douban.com/subject/26920875/ Author: Tao Yongyi Translator: Congee Reviewer: Brian

3.4. 需求的层级

Chapter 3.4. The Hierarchy of Demands

就自身的特点而言，需求是按层级划分的，大的层级可以分为生存性需求、舒适性需求、享乐性需求、炫耀性需求（或叫奢侈性需求）及投资和投机性需求。不同层次的需求对价格变动的反应具有不同的弹性。生存需求属于刚性需求，对价格变动的弹性较低。舒适性需求和享乐性需求对价格的变动比较敏感，在未被完全满足时，会对价格变动表现出较大的弹性。炫耀性需求与价格是反向运动，价格越高才越有炫耀的效果。比如手机刚刚出现时，一部动辄几万元的手机会产生炫耀性需求，当时拥有手机是成功人士的标志。而当手机价格普遍下降，连扫大街的都人手一部时，在手机上的炫耀性需求就减弱了。投资和投机性需求对价格本身不敏感，但对价格的预期敏感。在大宗商品市场上，一种商品（比如石油）从30美元上升到100美元，并不意味着需求量会减少（像主流经济学的需求曲线所预测的那样），如果市场普遍预期石油价格会涨到200美元，需求量不仅仅不会减少，反而会增加。反之，当石油价格从149美元跌到100美元时，如果市场普遍预期价格还会下降，这时的投机性需求不像需求曲线所假定的那样逐步增加，而是会进一步减少。不同层次的需求对应着不同的需求曲线和不同的行为特性，必须分别加以研究。

Generally speaking, different demands can be roughly divided according to their characteristics into the demands for survival, comfort, entertainment, flaunting (aka luxury), and investment/speculation. They constitute a hierarchy of demands in which its levels respond differently to price changes. The demand for survival is largely rigid and has little elasticity regardless of price changes. In contrast, the demands for comfort and entertainment are sensitive to price changes and show greater flexibility to price movements when they are not yet satiated. The demand for flaunting moves in the opposite direction of the price change since only expensive items are suitable for flaunting (in fact the more pricy the better). For example, when cell phones were first commercialized, a cell phone that costs tens of thousands could create a demand for flaunting, since the possession of a cell phone would hint at one's financial success. But as of today, with low prices affordable enough for everyone on the street to carry a phone, there is little demand in having a cell phone just for the sake of flaunting. The demand for speculation is sensitive not to the price itself but to the future price (i.e., the expectation of the price). In the market of commodities, the demand does not necessarily decrease if the cost of something rises, which is contrary to the general prediction of conventional economics. When oil price increases from $30 to $100, if the market foresees the future oil price to be $200, the demand will not decline but increase. On the other hand, when the oil price falls from $149 to $100, if the market expects the price to be going down even further in the future, the demand for speculation will decline as the price drops. This is contrary to the demand curve given by conventional economics. These different demands correspond to different demand curves and behaviors, and must be studied separately.

生存需求是一切需求的基础，当生存需求都无法满足时，其他一切需求都无从谈起。这不仅是对个人而以，而且对于整个社会来说，也是如此。如一个社会的多数成员基本的生存需求都没有满足，这个社会就会处了极度不稳定状态。

The demand for survival is the foundation that underlies all other demands. All other demands would be irrelevant if survival still remained a question. This is true not only for individuals but also for the society as a whole. A society would be extremely unstable if most of its members were struggling for survival.

生存需求对应的是基本生存资料，它主要包括食品、衣物和最低限度的栖身之所。这一部分的需求弹性很小，不能指望通过价格变动来调节它的数量。很多社会是用最低生活保障来满足这一部分需求的，在没有实行最低生活保障的社会，政府通常采用非市场手段来保证这部分基本生活资料的价格稳定。生存性需求会受到大的自然灾害、严重的经济危机和战争等极端情况的威胁，在这种情况下，如果任由市场自发调节，很容易给不法奸商囤积居奇、哄抬物价提供机会。使本来就十分严重的生存资料的供需矛盾，变得更加尖锐。

The demand for survival corresponds to the basic living necessities, mainly including food, clothing, and minimal shelter. This demand has very little elasticity, and cannot be readily adjusted by price changes. Many societies safeguard this demand with the minimum living standard guarantee, and at other places where such guarantee is absent, the government often stabilizes the cost of basic living necessities by non-market means. The demand for survival can be threatened by natural disasters, severe economic crises, wars, etc., in which case the automatic response of the free market may easily provide opportunities for unscrupulous profiteers to hoard and raise prices. Their activities can worsen the situation and exacerbate the shortage.

生存性需求的刚性特征，以及需求曲线几乎是重直的特性，使人们对这部分需求进行价格调节失去了任何意义，如果有哪位经济学家主张生存性需求会因价格的提高而减少，从而建议提高价格以达到抑制需求的效果，他要么是没有良知，要么是缺乏常识。

Because of such inelasticity, the demand curve is basically vertical. As a result, price adjustment becomes meaningless for the materials involved. Any economist who argues that the demand for survival responds to a rising price of goods and advocates for cutting the demand by price increases lacks either conscience or common sense.

舒适性需求与享乐性需求是指在生存需求之上、满足消费者各种身心享受的需求。就发生的领域而言，舒适性需求和享乐性需求与生存性需求之间有重叠的部分。比如食物，吃饱是生存性需求，吃得有营养和吃得美昧，是舒适性需求和享乐性需求；衣物能遮风避雨是生存性需求，但要穿得美丽、时尚，则是舒适性需求和享乐性需求。当然，舒适性需求和享乐性需求更多地发生在与生存性需求无关的领域，比如看电影、听乐会、出国旅游，等等，它不是生存需求的简单叠加，而是更高档次和更宽领域的消费选择。

The demands for comfort and entertainment arise after the consumer is no longer troubled with subsistence and develops various needs for physical and mental pleasure. These demands are a continuation of the demand for survival. For example, when it comes to food, one starts craving for nutrition and taste after one is freed from hunger. As for clothing, beauty and style are the concerns that come after the basic protection of one's body. Surely enough, some demands for comfort and entertainment have nothing to do with survival, e.g., seeing a movie, going to a concert, traveling to a foreign country, etc. They are not mere overlays of the demand for survival but rest upon consumer choices of goods in a wider range and at a higher level.

舒适性和享乐性产品的需求对价格变动比较敏感，因为这些产品不是必需品，需求弹性较大。另外，由于选择范围比较宽泛，它的可替代性会比较强，比如音乐会的票价比较贵，人们可能会选择去看电影或KTV。舒适性和享乐性需求的第三个特点是比较个性化，原因在于享乐性需求受个人偏好支配，它的分布特征很难用理性来解释。舒适性和享乐性需求的第四个特点是示范效应，即某一个舒适性或享乐性需求会在一个短时期内形成潮流。多数人会追随这种潮流，形成一段时间的消费热潮。

These demands are sensitive to price changes and have high elasticity, because the products are not essential for survival. Besides, since choices are available in a wider range, one option can be easily replaced by another. For example, if the concert is costly, people may opt to go to a movie or try karaoke. In addition, these demands are dominated by personal preferences, and preferences are not readily rationalized. Finally, trends are an important concern with regard to comfort and entertainment. A trend may form within a short period, during which time many people may follow and the consumption of the trendy product will surge.

炫耀性需求是消费者显示自己与众不同的需求，它对应的是奢侈品。这部分消费主要满足的不是消费者的感官刺激，而是提供心理上的满足，即显示自己的财富与地位。这部分商品的消费者更在乎奢侈品的社会意义，比如带花园和游泳池的豪宅、豪华汽车、私人游艇和私人飞机等，拥有这些产品等于佩戴了一个成功人士或上流社会的徽章。价格高昂是这些产品的特征。价格的调节，对这些需求的作用微小。如果价格降得过低，该产品反而会退出炫耀性需求的行列。价格高不可攀正是这些产品成为炫耀性需求选择对象的理由。炫耀性需求对整个社会的消费有引领作用，今天的奢侈品，可能会是明天的普及品。比如汽车和手机都曾经是炫耀性产品，但在今天，它们已经成为大众消费品了。由奢侈品转变为舒适型和享乐型产品。

Consumers show how unique and different they are with luxury goods, which correspond to the demand for flaunting. These goods provide psychological satisfaction more than sensory satisfaction because a person may demonstrate one's wealth and social status with the ownership. The consumers of such goods, e.g., high-end homes with gardens and swimming pools, luxury cars, private yachts, private jets, etc., care more about the social implications of the products, since the ownership is equivalent to a badge of social success or membership of the higher class. The luxury goods are typically highly expensive, and price changes have little effect on their demand. In fact, if the price becomes low enough, these goods will be delisted from the luxury category. The unattainably high price is exactly why these goods become the subjects in the demand for flaunting. Such demand plays a leading role in the consumption of a society, since a luxury today may become a routine item tomorrow. For example, cars and cell phones were once luxury items but have become consumer goods for the general masses. In other words, they left luxury and became the products in the demands for comfort and entertainment.

投资性需求也可以理解为发展性需求，这是人们为了取得更高收入而产生的需求，它的标的不是生活资料，而是生产资料和投资品，如股票、债券等。在某种意义上说，对教育和培训的投入也属于投资性需求。

The demand for investment may also be regarded as a developmental demand and it results from people's pursuit for higher income. The subjects of such demand are not the materials for consumption but for production and investment (equity, bond, etc.). Broadly speaking, education and training also qualify as a form of investment.

投机性需求在经济学教科书上是一个空白，凯恩斯在他的《就业、利息和货币通论》中，曾经提到过“投机动机”。不过，这只是他用来解释流动性偏好之所以会出现的一个原因。并没有说明在商品价格上，投机性需求会发挥什么作用。弗里德曼的货币模型也有投机性需求的变量，但它主要用来解释对货币的需求，没有解释投机对商品需求的影响。

The demand for speculation has remained an untapped arena in the teachings of economics. In "The General Theory of Employment, Interest and Money", Keynes mentioned the “speculative motive” but only used it to explain liquidity preference. He did not mention the effect of the speculative demand on the commodity price. On the other hand, the "speculative demand" is also a variable in Friedman's currency model, but it is mainly used to explain the demand for currency instead of the demand for goods.

在当今社会，投机性需求已经占到了许多商品交易的大部分，有些甚至是绝大部分的交易量。无视投机性需求的存在，就无法解释现代社会商品价格运行的规律，也无法解释经济周期的巨大波动特性。历史上著名的“郁金香事件”、“南海泡沫”、“密西西比公司”、1929~1930年的大萧条、20世纪末的亚洲金融危机以及美国次贷危机，都能看到投机性炒作的背景。

Nowadays, speculative demand underlies a large number of (if not most) transactions of commodities. Without taking into account speculative demand, the pattern of price changes in today's world cannot be rationalized, and the gigantic economic booms and busts cannot be explained either. Speculation is a key factor in various famous events throughout history, including the tulip mania, the South Sea bubble, the Mississippi bubble, the Great Depression in 1929–1930, the Asian financial crisis in the late 20th century, and the US subprime crisis.

投机性需求的第一个特点是与消费无关，这是为卖而买的需求和为买而卖的需求，即我们通常所说的买空卖空。所以，新古典经济学将消费与需求视为等同的理论无法解释它的运行规律。

The first characteristic of speculative demand is that it has nothing to do with consumption. The "consumers” buy only to sell and sell only to buy (also known as short selling). As a result, it cannot be explained by neoclassical economics, which considers demand as the equivalent of consumption.

投机性需求的第二个特点是，它不对价格做出反应，而只对价格的预期做出反应。不管价格涨到多高，只要投机资金认为还能上涨，对投机标的需求就不会下降，反而会上升。同样的道理，不管价格降到多低，只要市场预期价格还会再低，投机性卖出就不会停止，而投机性需求也不会因为绝对价格下降，就增加买入。这与新古典经济学所描述的供求规律完全不同。新古典经济学家把需求作为价格的函数，价格降低需求量会相应增加，价格升高需求量就会降低，因而需求曲线是一条从左上向右下倾斜的曲线；供给的情况正好相反，价格上升供给量增加，价格下降，则供给量减少。

The second characteristic of speculative demand is that it responds not at all to the price but only to the expectation of the price. Even if the price is already exorbitantly high, speculative demand will continue to rise so long as the price is expected to grow further. Similarly, an absurdly low price will continue to drop as long as the market expects further declines ahead. Since the demand is speculative, buying will not increase and the speculative selling will not stop only because the price is going down. This is completely different from the law of supply and demand in neoclassical economics. Demand is a function of price in neoclassical economics, and the rise and fall in the price will decrease and increase the demand, respectively. In this way, the demand curve slants from the top left to the bottom right. The converse is true for supply, which rises when the price goes up and drops when the price goes down.

可是，我们在大宗商品市场和资本市场中看到的情形却完全不是如此。当大宗商品或资本市场价格跌到最低时，成交量也会降到极低的水平，而每当市场创出历史新高时，成交量也会成倍地提高。所以有“地量地价，天量天价”的说法。这主要是由于投机性需求追随的是价格的预期，而不是价格本身。即使价格比最高价格跌去2/3，如果投机者认为价格还要下跌，他就不会买入。反之，即使价格上升了200%，但如果投机者认为价格还会再上升50%，他仍然会继续买入。供给的情况也是如此，当价格上升形成上涨的预期时，供给方会惜售，而不是增加供给，如果价格下跌引起进一步下跌的预期，即使价格跌去了2/3，人们还是会加大卖出。所以，新古典经济学关于需求与供给是价格的函数这一说法，完全不适合投机性需求。对于消费性需求，只适合于舒适性和享乐性需求未满足的阶段。因为投机性需求不会进入最终消费，所以它不受需求饱和度的制约，也不受效用的约束，只受资本存量的制约。它所反映的需求是一种虚假需求。新古典经济学的一般均衡理论认为，价格对供给和需求的调节，可以导致市场自动趋向于供需的均衡。这个论断显然是没有考虑到投机性需求的特点，目前价格的高低对投机性需求不会有影响，而未来价格的高低才会对它有影响。由于预期有不确定性，预期的发展有一个自我加强的过程，当一个上涨的预期被确定时，就会吸引更多的投机性买盘进入，从而推动价格进一步上涨，进一步上涨的价格又会带来更强烈的上涨预期，从而使价格上升得更加猛烈。上升的预期与上升本身会形成一个正反馈回路，使上升势头由弱变强，直到疯狂，把价格推到一个匪夷所思的水平。一旦价格趋势改变，所有原来的投机性需求会变成投机性供给，使供求关系发生180°逆转。而价格下跌的预期又会形成一个相反的自我实现的过程，下跌的预期会造成价格的进一步下跌。

However, this is not what happens in the commodities and capital markets. When the price in the commodities or capital market falls to a minimum, the transaction volume also drops to a record low, and conversely, whenever the market hits a record high, the transaction volume will increase exponentially. Thus the saying “floor volume for floor price, ceiling volume for ceiling price." This is because the speculative demand pins on the expectation of the price but not the price itself. Even if the price of a good has fallen 2/3 from the peak, the speculators will refrain from buying it if they think the price is still going to fall. Conversely, even if the price has already risen by 200%, the speculators will continue to buy if they believe the price will still rise by another 50%. The same is true for the supply. The suppliers will refrain from selling rather than increase the supply if the rising price generates an expectation of additional increase, and will strive to sell when the decline of the price (e.g., by 2/3 already) leads to the expectation of a further drop. Therefore, the axiom in neoclassical economics that demand and supply are functions of the price is completely unsuitable for speculative demand. Such an axiom is only suitable for the demands that involve genuine consumption, more specifically only applicable to the unfulfilled demands for comfort and entertainment. Since speculative demand does not culminate in an eventual consumption, it is limited neither by the saturation of demand nor by the constraints of utility. It is only restricted by the available capital and reflects an unreal demand. The expectation evolves in a self-reinforcing manner because of its inherent uncertainty. An expected rise will attract more speculative buying, which in turn drives up the price even further. This positive feedback eventually pushes both the momentum of the trend and the price itself to an absurd level. As soon as the trend reverses, the speculative demand will immediately become the speculative supply and invert the relationship between supply and demand. This U-turn again creates a self-realizing loop in the opposite direction, in which the falling price leads to the expectation of constant price decreases and vice versa.

投机性需求造成的价格大起大落，会使消费需求也带上投机的色彩，在预期价格下跌时，消费者会把消费维持在即时消费的最低水平，以防止在价格较高的水平上买入并不急需的商品。而在形成价格上涨预期时，则加大超过正常需求的买入量，以抵消未来价格上涨的风险，这种行为，会进一步加大价格波动的幅度。

The drastic price fluctuations caused by speculative demand may alter the genuine demand for consumption as well. For example, when the price is expected to fall, consumers will try to keep their immediate consumption at the lowest level to prevent buying goods at a high price that are not urgently needed. Conversely, when the price is expected to rise, consumers will stock up goods and make extra purchases that exceed their normal demand to offset the risk of future price increases. These behaviors will further exacerbate price fluctuations.

我们在大宗商品交易的市场上看到，期货合约中到期末平仓合约占合约总数不到2%，这是真实需求——套期保值合约所占的比重。而98%以上的合约都是投机性合约。资本市场中也有这种情况，中国资本市场的年均换手率平均在800%以上，真正进行长期投资的人可以说凤毛麟角。如此大比重的投机性需求，会给商品价格带来多么大的波动是可想而知的。然而，这种由投机性需求放大的价格信号却是不真实的。它把真实的需求放大了数倍甚至数十倍，这部分投机性需求推高的价格很容易给产业资本发出错误的信号，使资源大量涌入被投机性炒作抬高价格的生产领域，一旦趋势逆转，这部分投机性需求就会出现反方向性的运动，导致商品价格大幅回落。

In the commodities market, only less than 2% of the futures contracts are closed on their expiration date. These reflect the genuine demands that come from hedging, whereas the others, accounting for more than 98% of the total contracts, are speculative. The situation is similar in the capital market. For example, the average annual turnover rate of the capital market in China exceeds 800%, which means very few people are making long-term investments. It is not hard to imagine how much fluctuation in the price will be generated by such a gigantic amount of speculative demand. However, the price radically distorted by speculative demand is an unreal signal of the genuine market demand. When the price is driven to high levels by speculative demand, the price sends wrong signals to industrial capital and attracts a huge influx of resources into the production of speculated goods. As soon as the trend reverses, the speculative demand will act in the opposite direction and the price will then fall sharply.

投机性需求不仅仅局限于大宗商品和资本市场，它可以瞄准任何产品，只要它预期某种商品会出现短缺，就会伺机而动。中国人耳熟能详的就有兰花、宠物、普洱茶、绿豆、大蒜、玉石、邮票、红木、古玩等，几乎无所不包。投机性需求追求的是波动，波动幅度越大，对投机性需求的吸引力就越大。如果没有波动，它们就会去创造波动。全部问题在于，新古典理论假设价格会对需求产生决定性的影响，当综合性需求更多地受价格预期的影响时，市场行为就会完全不同。因为这时市场追求的不是供需平衡，而是追求供需的不平衡。无视投机性需求的在在，使主流经济学在解释大宗商品的价格运动和资本市场的运行规律上，显得十分苍白无力。

Speculative demand is not limited to the commodities market and the capital market but can involve any product. Any goods with an expected shortage can fall prey to speculative demand. Well known examples in China include orchids, pets, the Pu'er tea, mung beans, garlic, jade, stamps, mahogany, antiques, etc... The list basically never ends. Speculative demand loves volatility, i.e., the greater the fluctuation the better. In fact, it would actually create fluctuation for itself. This makes neoclassical economics problematic, which assumes that the price has a decisive impact on the demand, since the market behaves in a completely different way when the combined demand is more strongly affected by the expectation of the price, in which case the market approaches not the balance but the imbalance between supply and demand. Conventional economics is very poor at explaining the price movements in commodities market and the operation of capital market because it ignores the speculative demand.

现在我们有了市场中几种不同层次的需求，这些需求对应着不同的商品层级，满足这些需求的行为具有不同的特征。它们共同构成了人类需求的层级结构，并且对生产行为产生着重大影响。当某一层次的需求满足后，就会产生需求层次的升级。我们用图3-10来表示需求提升与经济发展之间的关系。

In the above we have laid out varous demands that correspond to goods at different levels and different market behaviors that meet these demands. The different levels constitute a hierarchy of human demands and have a major impact on the production of goods. With the demand at a certain level satiated, a new level will open to consumers as an upgrade. Figure 3-10 illustrates the relationship between escalating demands and economic development.

图中左侧最低的那个不规则梯形，表示的是生存必需品的需求及满足点，在未达到满足点之前，梯形的上沿是向下倾斜的，代表需求是随价格的下降而增加。人类经济发展的结果，不是新古典所描述的那种单纯数量的增加，而是人类需求不断向更高层次发展的过程。人类好像是在一个欲望的阶梯上攀登，不断从一个需求层级迈向一个更高的需求层级。

The lowest trapezoid on the left indicates the demand for the survival necessities as well as its point of satiation. The upper edge of the trapezoid inclines downward because the demand decreases with rising price before the satiation.

人类经济发展的结果，不是新古典所描述的那种单纯数量的增加，而是人类需求不断向更高层次发展的过程。人类好像是在一个欲望的阶梯上攀登，不断从一个需求层级迈向一个更高的需求层级。

The economic development of human society is not a simple increase in the number of goods, as described by neoclassical economics, but a process of continuous development of demands from one level to another. It is like climbing a ladder of desire and constantly stepping onto higher rungs.

图中的虚线是投机性需求引起的价格震荡的假想图形。在需求升级的过程中，如果各个部门的交换出现了不协凋的状况，有些产品出现了产能过剩，而另一些产品则出现了短缺，投机性需求就会兴风作浪，使价格出现大幅震荡。

The dotted line in the figure depicts the potential price shocks caused by speculative demand. When the exchanges between various economic departments fail to coordinate, i.e., too many of some products are made and too few of others , the speculative demand will crop up and perturb the price.

在主流需求饱和时，要求有新的需求和新的产业升级来取而代之，如果新的产业革新没有及时跟上，形不成新的增长点，传统行业的生产过剩就不可避免。当新旧需求转换完成时，经济体就会进入新一轮增长。由于这个话题已经进入了宏观经济学的范畴，我们把它放到第12章去讨论。

New demands and industrial upgrades are necessary for economic growth when a conventional demand is satiated (i.e., saturation). Overproduction in traditional industries will be inevitable if the industrial upgrade fails to keep up and generate new economic growth points. The economy will enter a new round of growth when a new demand replaces an old one. This topic falls into the realm of macroeconomics and will be discussed further in Chapter 12.