May 01 2008

From the Help Desk: the money multiplier and new money creation

Question about the money multiplier – Welker’s Wikinomics Page

The following question was submitted by “blobber008” to the discussion forum at our class wiki:

When I need to find the maximum increase in the total money supply, where the money deposited is \$100 and the reserve requirement is 10 percent, do I multiply the total money deposited by the money multiplier, or do I multiply the excess reserves by the multiplier to find the increase, or does it depend on the situation? I thought that I would multiply the initial deposit by the multiplier, thus getting an increase of \$1000. My answer key, though, said that increase is \$900. When I asked my teacher, she said that you subtract out the original \$100 from the \$1000 to get the increase in money supply.

The reason I’m confused is that another question asking for an increase resulting from the Fed buying securities from the public doesn’t subtract out the original value. Do you do something different when dealing with money in a bank/checking account and the purchase of securities? Or, do I really subtract out the initial deposit? If so, can you explain why?

This is a good question and one that often comes up among students and even teachers via the AP Economics teacher email group.

The basic difference between an individual depositing \$100 and the Fed buying \$100 worth of bonds from a commercial bank is that when the individual deposits money, it was already part of the money supply. This is is why the amount of new money created is only \$900 when an individual deposits \$100 in the bank. We multiply the \$100 by the money multiplier (1/required reserve ratio), and then subtract the original deposit, since it was already held by the public, thus part of the money supply.

In the case of the Fed’s purchase of bonds, on the other hand, the \$100 of new reserves at the bank are themselves new money, since money held by the fed is not part of the money supply. In this case, we multiply the change in deposits by the multiplier, and the new money created includes the initial change in deposits, which came from the Fed.

Thanks for your submission, hope that helped!

Jun 03 2007

Gambling, prostitution and theft rampant among Yale monkeys

Freakonomics: Monkey Business: Keith Chen’s Monkey Research

No I’m not talking about the latest freshman class at an Ivy League school… rather a group of monkeys at Yale that have been taught how to use money:

The essential idea was to give a monkey a dollar and see what it did with it. The currency Chen settled on was a silver disc, one inch in diameter, with a hole in the middle — ”kind of like Chinese money,” he says. It took several months of rudimentary repetition to teach the monkeys that these tokens were valuable as a means of exchange for a treat and would be similarly valuable the next day. Having gained that understanding, a capuchin would then be presented with 12 tokens on a tray and have to decide how many to surrender for, say, Jell-O cubes versus grapes. This first step allowed each capuchin to reveal its preferences and to grasp the concept of budgeting.

Turns out the law of Demand is not only true for humans but for monkeys too. When Chen “lowered the price of grapes”, monkeys would buy more grapes and less Jell-O, following the basic rule of utility maximization. Interestingly, the introduction of money led to more than just the simple exchanges of currency for candy and cucumber; the monkeys were also taught to gamble. Through their observations of several gambling scenarios, the researchers found monkeys tended to display “loss averse” behavior in games of chance, leading to an amusing conclusion:

The data generated by the capuchin monkeys, Chen says, ”make them statistically indistinguishable from most stock-market investors.”

Sadly, gambling was not the only vice that accompanied the introduction of money in to monkey society:

Then there is the stealing. Santos has observed that the monkeys never deliberately save any money, but they do sometimes purloin a token or two during an experiment.

But the debauchery does not stop with gambling and theft:

Perhaps the most distinguishing characteristic of money, after all, is its fungibility, the fact that it can be used to buy not just food but anything. During the chaos in the monkey cage, Chen saw something out of the corner of his eye that he would later try to play down but in his heart of hearts he knew to be true. What he witnessed was probably the first observed exchange of money for sex in the history of monkeykind. (Further proof that the monkeys truly understood money: the monkey who was paid for sex immediately traded the token in for a grape.)

As if we needed any proof beyond the widespread immorality and loss of values that distinguish many rich human societies, the steep decline of monkey morality observed at Yale can only be attributed to the introduction of currency! The implications of the Yale study on economics are clear: humans are not necessarily unique in our understanding of currency as a means of exchange. As long as money has imbued human societies, the wont to enrich ourselves through immoral means such as gambling, theft and prostitution has stained civilizations from ancient Mesopotamia to modern America.

When taught to use money, a group of capuchin monkeys responded quite rationally to simple incentives; responded irrationally to risky gambles; failed to save; stole when they could; used money for food and, on occasion, sex. In other words, they behaved a good bit like the creature that most of Chen’s more traditional colleagues study: Homo sapiens.

To make a more poignant observation, one thing is clear and disturbing, among the human societies today, Americans are most like monkeys when it comes to saving.

Discussion Questions:

1. Of the various functions of money, which role does money play for monkeys?
2. What gives the money used by the monkeys its value?
3. Discuss the evidence from this article suggesting that monkeys follow the law of demand.
4. What is the utility maximization rule and what evidence from this article supports the suggestion that monkeys follow this rule?
5. How are monkeys more similar to American consumers than to, say, Japanese or Chinese consumers?

« Prev

• Order Welker’s books

for IB Economics

for AP Macro