Ruminations on the Law of Demand

Two events today caused me to start thinking on the Law of Demand and its power as an explanatory tool.

The Law of Demand in Medical Care

When I lecture on the Law of Demand, which simply states that all else held equal as price rises quantity demanded falls, I inevitably get the objection: “What about necessities like food, water, health care?”

Even for these supposed necessities, the Law of Demand applies. Relatively high prices cause people to search for alternatives. One such example of this is in the Bob’s Burgers episode “Sexy Dance Healing” (Season 6, Episode 8). The titular character, Bob Belcher, goes out on a walk to try and gain inspiration for his Burgers of the Day (a running gag in the show. Each of the Burgers of the Day are usually pun-named, such as the “Never Been Feta Burger” (comes with feta cheese)). While walking past a message parlor storefront, Bob slips on oil poured on the sidewalk and tears his labrum. Bob goes to the doctor who informs him he’ll need surgery and his deductible is super-high: “like, $6,000 high.”

As per the Law of Demand, Bob begins to consider different options to pay for the surgery he wants but cannot afford outright. He considers suing the store that poured the oil on the sidewalk. He even goes so far as to have his lawyer serve notice, but the masseuse offers Bob a deal: the masseuse insists he can heal Bob without surgery. If Bob is not healed after 10 sessions, he will pay for Bob’s surgery.

So, the lesson from this story: the relative price of Bob’s surgery was high. Even though Bob needed medical care, the high price caused him to search for alternatives (spoiler alert: the alternative Bob chose worked out well). The doctor’s price of surgery was too high. If he lowered the price, Bob would participate; in technical terms, if the price fell, Bob’s quantity demanded for labrum surgery would increase.

A high price of medical care causes people to seek alternatives. A diabetic may try to change their diet. A person suffering arthritis may seek holistic approaches. A person suffering from psoriasis may move to a more humid climate. Et cetera. That these people seek alternatives, thus implying that if the price was lower they’d consume more of the good in question, indicates that the Law of Demand holds even in the case of medical care.

The Law of Demand and Power over Consumers

The second example of the power of the Law of Demand comes from the realm of trade. Commenting on this Cafe Hayek post, Jorod Smith writes:

Voluntary exchanges are nice. Now what happens when one country becomes so dependent on imports from and exports to one other country? The other country actually controls the country that relies on it for imports and exports. This is exactly the problem we have with China. 

Mr. Smith’s fears are unwarranted. Imports and exports do not equate to “dependence” on another individual, regardless of how much they might make up your trade. Currently, 100% of my food comes from sources external to me, namely Wies Supermarket. I grow none of my own food. However, despite this, Wies holds exactly no sway over me. They cannot dictate to me in any way, shape, or form my behavior. If Wies were to try to jack up prices or exert some other kind of pressure on me, I could easily go to another competitor. But what if there is no other competitor? Then I would seek other alternatives: I could grow my own food or seek some other substitute (consume less food, switch to things that get me more calories per dollar, etc). In other words, they’d have no influence on my behavior as I could seek alternatives.

To bring this back to China, if the Chinese government were to try to impose some preferred policy on the US by threatening trade disruptions, it’d be as ineffective as the US blockade was in forcing the Castros out of power in Cuba or the Kims out of power in North Korea. Economic sanctions tend to be very ineffective. Why? Because of the Law of Demand. As relative prices rise, people start to seek alternatives. In the case of the Castros, it caused them to look toward the Soviet Union. In the case of the Koreans, it caused them to look toward the Chinese. If the Chinese were to try to threaten something, US consumers could seek other competitors. If none are available, they could turn inward. Indeed, this is why the attempt by the Chinese to jack up rare earth metals prices failed.

Conclusion

In his classic book, The Theory of Price, George Stigler writes of the Law of Demand:

How can we convince a skeptic that this “law of demand” is really true of all consumers, all times, all commodities?… Perhaps as persuasive a proof as is readily summarized is this: if an economist were to demonstrate its failure in a particular market at a particular time, he would be assured of immortality, professionally speaking, and rapid promotion while still alive. Since most economists would not dislike either reward, we may assume that the total absence of exceptions is not from lack of trying to find them. And this of course hints at the real proof: innumerable examples, ranging from the wife who cuts down on strawberries because they are out of season ( =more expensive) to elaborate statistical investigations, display this result.

Pgs. 22-23

The Law of Demand remains an extremely powerful tool. Indeed, one can build all of price theory off of it. My above two examples show its utility. A thorough understanding of the Law of Demand can get one very far.