Rate of Time Preference

  

Categories: Investing, Metrics

Hmmm...you need to mow the lawn. You also want to catch that Zodiac Killer movie starring Ted Cruise before it’s out of theaters. Which will you do now, and which will you do later?

Your answer may reveal your rate of time preference. Time preference is what economists, psychologists, and others call it when someone treats their immediate selves different from their future selves.

In the famous marshmallow test, kids were given one marshmallow. They were told they could eat it now...or, if they can wait and not eat it, they’ll get another one later, and have two. The kids who ate the marshmallow right away, going for immediate pleasure over double rewards, had a high time preference. The kids who were patient enough to earn the second marshmallow had lower time preference. Those kids were able to keep in mind their future selves over just their present-moment selves.

It turns out that this might be an important thing for how the rest of your life goes. The study showed that kids who had the patience to wait for the second marshmallow...with lower time preferences...did better in some areas of life than the kids with higher time preferences.

How do we chart the difference between “high” and “low” rates of time preference? In neoclassical economics, the rate of time preference is a parameter of a person’s utility function. It shows the tradeoffs of consuming something today versus in the future.

Do you have the strength to put off watching the movie, an enjoyable activity? Do you have the strength to not procrastinate a not-so-enjoyable activity, like mowing the lawn? The more impulsive you are rewarding your current self, and the worse you are a procrastinator, the higher your rate of time preference.

Rate of time preference models can be modeled on wider scales, looking at the time preferences of smokers (who know that smoking often leads to cancer), people who aren’t saving for retirement (thinking "I’ll do that later"), and other time-sensitive actions.

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Finance: How Do You Calculate Rates of R...35 Views

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finance - a la shmoop how do you calculate rates of return? well invest a dollar get

00:08

more than a dollar back right? well yeah you hope so anyway in in finance land [dollar bill on table]

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and Wall Street and any other professional gig. well rates of return

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from financial investments are generally stated as annual returns, so calculating

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a rate of return revolves around the one year at a time thing. there are a ton of

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curveballs that get thrown into these calculations. here's a big one,

00:33

dividends. well guess what clueless financial journalists with little to no [dividends defined]

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real schooling in finance quote stock market returns all the time. let's say

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that shares in random example industries traded at the same price at the

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beginning of the 1970s as they did at the end of the decade. prices for random

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example industries were totally flat from 1970 to 1980. that's what one of

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those journalists might say. and they don't even get fired for making such a [man reports news]

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narrow statement .no nothing happened at all. and wrong. had they taken this course

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they'd have realized that monster-sized dividends were paid out during that time

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period. five six seven eight percent a year, each year. yet the journalists

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ignored them when they stated that the stock market was in fact flat for a

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decade and maybe shares of that company were also flat for a decade. but it

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implied that they got no return from their investment which is absolutely [icons of stock market and a stock deflate]

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wrong. did readers get their money back for that bad journalistic work? yeah we

01:30

doubt it - well what about zero coupon bonds? that is their bonds that pay no

01:35

dividends or interest along the way and they sell at a discount to par. what does

01:40

that mean? that is $1,000 par value bond pays you a grand in seven years. well how

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do you calculate the annualized rates of return there? well today that bond sells

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for six hundred forty two dollars. like you buy it today for six hundred forty

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two you get a thousand bucks in seven years. well what's the rate of return on [zero coupon bond rates of return listed]

02:00

that bond? hmm. well vanilla bonds like these we're a whole lot easier to

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calculate. because like you got the interest rate right there on the thingy.

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yeah so the question is really what interest rate will accrue and then

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compound for this bond such that in exactly seven years you get a thousand

02:17

bucks? well if it compounded at ten percent a year the compounding would

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look like this. you see the table right there and whoa we've already passed the

02:25

grand way ahead of seven years. so the compound rate must be less than ten

02:28

percent right well what if it compounded at five percent a year well then the [compound rate listed]

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rates of return would look like this and basically we're just multiplying 1.0

02:36

five times a 6.2 and we take that compound totally multiply 1.05 again and

02:41

so on and so on. much closer .well here's the formula you'll want to remember.

02:45

where f is the face value PV is the present value and n is the number of

02:53

periods. well in our example the face values a thousand bucks, the present

02:58

value is 642 dollars and the number of periods is the number of years or seven

03:05

years. all right well then we just you know put our handy-dandy calculator to [mathematical formula shown]

03:08

work and get a yield of well right around here. so here's the key idea rates

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of return are an annual thing when quoted among finance professionals. among

03:20

fun dance professionals well and maybe a different story. [three stooges pictured]

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