In a 2005 blog entry from economist and George Mason professor, Bryan Caplan disputes the veracity of time preference proving why interest rates tend to be positive. Time preference asserts that people prefer present consumption over future consumption. Providing some insight into why people would be willing to receive money now and later pay it back with interest. From the standpoint of an individual’s assessment of value, $1000.00 today is worth more than $1000.00 three months from now. Dr. Caplan launches a two-pronged attack against the assumption that time preference explains why interest rates are positive. Caplan suggests that dimmishing marginal utlity, not time preference demonstrates the proclivity of interest rates being positive.
Professor Caplan’s first point regarding the failure of time preference to adequately explain positive interest rates relates to the allocation of nonmonetary resources. He details a scenario where an individual is marooned on a desert island with only two bananas. Per a loose application of time preference, in theory, the person stuck on the island would eat both bananas today. Since we prefer present consumption to future consumption. A “perfectly patient” person would be willing to eat only one banana a day to more effectively curb their hunger. This is because we disvalue hunger today equally as much as we do tomorrow. Making dividing consumption between the two days a more effective use of resources.
Caplan goes further elucidates this point by demonstrating the fact that often in barter interest rates are negative. Per the blog entry:
“Suppose we knew the price of food would double next year. Then a pound of food now trades for half a pound of food one year from now. Translation: a negative 50% interest rate!
If this seems crazy to you, suppose the food was the only commodity, and you expect a famine next year. Wouldn’t you happily trade 2 pounds of current food in exchange for a promissory note good for 1 pound of food next year?”
This example explicates depending on the context we may forgo present consumption for future consumption. Even when we are expected to take a loss on the value of that commodity. This foils the main tenants of time preference. If we were to delay current consumption for future consumption we tend to do so for future gain. To quote the Austrian economist Roger Garrison “ We save up for something”. We hang on to stocks, gold, annuities, bonds, or cash holdings with the anticipation they will increase in value. It is important to note that inflation does take its toll on cash holdings. In the mind of the average person, it is more about amassing large quantities of money than an expected increase in value. Per time preference, if we did anticipate no gain from delaying consumption, we would be more apt to consume now than take the loss. However, in the situation presented by Dr. Caplan, it may be reasonable that a logical person may do the opposite. The rationale why loans for money tend to be positive is the fact that money does not spoil and is of little cost to store.
The second prong of Professor Caplan’s argument is the most compelling. In modern society, people have the ex-ante perception that they will be richer in the future. Anticipating being wealthier at a later date will drive a person’s demand for consumption up for the present. As the individual exhausts their desire to consume, the hope is that they have more money to pay back the sum that was loaned with interest. That is certainly a point that the Austrian perspective on interest rates ignores. Is it possible that if we excepted to get a raise in our compensation next year, we are more apt to spend more now and around the time we start to experience the disutility of consumption we experience a bump in pay? This is a very likely scenario. Presents arguably the biggest blind spot in the theory of time preference.
However, there is one looming question that Dr. Caplan does sidestep in his arguments. Few sane economists would ever argue that the law of diminishing marginal utility doesn’t apply to consumer behavior. But are we truly measuring the utility of the same commodities if we delay present consumption? Our Christmas decorations three weeks before December 25th the same commodity as these same decorations on the clearance rack the first week of January? It could be reasonable to argue no. While diminishing marginal utility could explain this decrease in demand, but it fails to consider the full scope of the customer’s subjective evaluation of the goods. The marginal utility can only explain the assessment of the value of a commodity. It cannot explain if the customer perceives the good as being categorically different. The variable of time could very well influence whether Christmas decorations now or a month ago are truly the same product. Applying this reasoning to interest rates, this point becomes quite clear. Is $1000.00 today plus avoiding a late payment on a credit card the same as $1,000.00 next week? Especially when we consider late fees, damage to our credit score, etc. On top of it, you still owe the credit card company $1,000.00. It is difficult to quantify the intrinsic value of having a clear credit score. $1,000.00 plus interest may be worth more to the individual than taking a hit on their credit score.