Just One More Bite: Thanksgiving Dinner and Marginal Utility

Roasted Turkey

Roasted Turkey (Photo credit: chooyutshing)

In keeping with both the theme of Thanksgiving and the theme of economics I thought it would be fun to figure out how we could use a mathematical model for marginal utility to determine at which point the satisfaction you’re getting from Thanksgiving dinner turns into dissatisfaction and possible nausea. We’ll use an algebraic model.

In this model:

S = Satisfaction

Vn= Serving number

B -1= Number of bottles of beer consumed ( Can substitute W for glasses of wine but change the exponent to – .5)

Z = Average Serving size A

( .5T + .5P + .4R + .1C + .3 + .1G + I  where T = slices of turkey, P = scoops of mashed potatoes, R = number of rolls, C = spoonfuls of cranberry sauce, F = scoops of stuffing, G = spoonfuls of green beans and I = slices of pumpkin pie. Weighting of each item was determined by a scientifically subjective estimation. )

The formula for total satisfaction is:

S = – Z Log Vn  + B -1

(Notice that satisfaction approaches infinity as V approaches 0. Anticipation, man, anticipation!)

So let’s say your average serving size equals 2, and you’ve had 2 bottles of beer. Here’s the graph of your marginal satisfaction:

Declining Marginal Utility of Thanksgiving Dinner

You can see that by your second serving you’re already in negative territory and taking deep breaths between bites.

But what if you’re normally a big eater? Then we can throw in a big eater modification by multiplying the beer appetite diminisher by .-1 (this also works if you’re a really fast eater).

S = – Z Log Vn  + B -1( -.1)

Now the graph looks like this:

Declining Marginal Utility of Thanksgiving Dinner for a Big Eater

As you can see, you can get halfway through that third serving before you have to unbuckle the belt or throw on some sweatpants.

Now by modeling the point at which each family member crosses into negative territory you can more precisely fix the number of servings everyone will eat thus allowing you to be more precise in the amount of each food item you need to buy for Thanksgiving dinner so that everyone is satisfied and no one ends up with indigestion. I think that is a worthy economic goal.

(I suppose we could take a derivative but my calc is very rusty. Maybe one of you can come up with a Thanksgiving dinner marginal utility function using a partial derivative.)

So enjoy that turkey wisely! Friends don’t let friends drive stuffed.


7 Comments on “Just One More Bite: Thanksgiving Dinner and Marginal Utility”

  1. Kris Kennedy November 21, 2012 at 3:24 PM #

    Extremely funny…you really do think deelpy, don’t you?

    • Robert-preneur November 21, 2012 at 10:48 PM #

      Thank you! Nah, it’s just my OCD. 🙂
      Happy Thanksgiving!

  2. Purnimodo November 21, 2012 at 10:32 PM #

    Ahw this post made me smile! Who says algebra is boring!! 😉 Like Halloween I hope this Holiday will catch on in Holland too.. and it just might!! Just read somewhere that many Pilgrims from the Plymouth Plantation came from my birth city Leiden.. 😀

    Och… The Turkey looks so yum. What’s the fun of having no indigestion every now and then?. it comes with the territory.. nothing better than going to sleep with a full belly, a little tipsy and many shared laughter. Leaving the oopsies for tomorrow 😉

    Happy and Blessed Thanksgiving!!

    • Robert-preneur November 21, 2012 at 11:33 PM #

      But of course! The Dutch had quite a presence in the New World. They founded New York City. Yay Dutch!
      It’s true that part of the Thanksgiving tradition is putting on 5 pounds in one night. It’s just not economically efficient. But who cares! Eat, drink and be merry Purnima.
      What’s happening in Holland this week? Any holiday celebrations before Christmas?
      Happy Thanksgiving Purnima. Here’s to gratitude for meeting new friends.
      Warmth and Peace

      • Purnimodo November 24, 2012 at 2:41 AM #

        Sinterklaas – A Turkish Christian saint that lives in Spain and comes each year, on December the 5th to Holland. On a steamboat, together with his helps and overstocked with presents. On the night of the 5th of December all children put their shoes in front of the fireplace (or electric heater) with some carrots and a little wish list. Sinterklaas will climb, while sitting on his horse Amerigo, the Dutch roofs. To throw presents though the chimney’s for all the kids that had been good.

        I think we poor Dutchies need help 😉

  3. Robert-preneur November 24, 2012 at 10:00 PM #

    Purnima, you’re nuts! LOL! Sinterklaas! And I suppose his helps include miniature French baristas who keep him plied with expresso so he can stay up all night while Mrs. Sinterkaas, a model from Singapore, nags him about not having enough ambition.
    I think you’re way off on your calling. You should probably write comedy. 🙂


  1. Happy Thanksgiving « LauraLovingLife - November 21, 2012

    […] Just One More Bite: Thanksgiving Dinner and Marginal Utility (teacher-preneur.com) […]

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