Inequality of Splitting the Bill

A few days ago, I blogged about the inefficiency of splitting the bill. (Cliff notes version: when you split the bill, your dining companions bear much of the cost of your ordering more. This gives you an incentive to order more than you would otherwise.)

Today, the inequality of splitting the bill. I should probably explain this. When I was a graduate student, I had a opposite-sex roommate. We are both foodies, and would frequently go out to eat together. When the bill came, we would each put down a credit card. We split the bill evenly. So far, not too interesting.

Half the time, the bill turned out to be odd (not even, e.g., $46.13). In this case, it wasn't possible to split the bill exactly. It was common to see the bill split $23.06 and $23.07, and also $23.00 and $23.13. One of us had to pay more. I (a male) and not my roommate (a female) was always given the larger amount to pay. This happened far too often to be explained by chance. I wish I had recorded these data, but we split the bill in this fashion this dozens of times; the outcome was always (or perhaps almost always) the same.

In our case, it was easy to match credit cards to patrons (one name is typically female, the other typically male). Based on this mini and accidental experiment, I guess men nearly always pay the extra penny. Economically, this extra penny isn't a big deal; it it dwarfed by the higher cost that women are forced to pay for a variety of sevices (e.g., dry-cleaning). Over the course of our meals, the difference probably added up to less than the cost of a latte at Starbucks.

Psychologically, I think this is kind of interesting. Did servers think I was more able to pay? That I wanted to pay more? That paying more (or all) was my "role"? I wonder what will turn up based on differences in race; I wonder if gender differences are larger or smaller if the dinner looks like a work function, a date, or a social gathering.

I'd love to get actual data on this, so if you feel like it please help me out with an experiment.

Who can participate? You can participate if:

1. you go out to dinner at a place that takes credit cards;
2. you go with other people and are willing to "split the bill", putting down one credit card per person;
3. some of your party could be reasonably identified from others in your party based on the names on your credit cards. This identification could be based on race, gender, or even age. (This would work well if Jennifer Smith (female) and John Jones (male) went out, or Jennifer Smith (Caucasian) and Jennifer Wong (Asian), or Mildred Smith (age 85) and Jennifer Jones (age 30). This need not work perfectly, as I'm sure there are plenty of Jennifer Smiths who are of Asian descent and plenty of Jennifer Wongs who are not.); and,
4. the final bill turns out not to be evenly divisible by the number of people in your party. For example, the bill is odd for a table of two.
   

How to participate?

1. If you get a bill that is not evenly divisible (e.g., $46.13 bill for two people), each person should put down a credit card with their name on it (which implicitly identifies whose credit card goes with each person).
2. If asked, say you want to "split the bill" or "split the bill evenly". Do not mention that this isn't possible to the penny.
3. Make a note of the following information and email it to me:

• The location of the restaurant, name of the restaurant, and the date you went.
• Your best guess about the age, race/ethnicity, and gender of the server (or the person who you think dealt with your credit card information), if possible.
• The name, age, race/ethnicity, and gender of each person in your party. Approximate ages/ethnicites are fine if you don't want to ask your dinner date's age or ethnic background. We just want to know what a server might guess about these things by looking at you and your names.
• The total bill amount (without tip) and how this amount was allocated among the people in your party.
• Where on the table (near which person, etc) did the server place the bill? Did the server ask you what you wanted done with the cards you put down?
• Did your dinner look to the server like an a) date, b) work function, c) social gathering of friends, or d) other (please explain)?
  

Thank you in advance.