The Diner's Dilemma

Ever been to a restaurant with a group of people (often friends) and end up splitting the bill, so everyone pays equally? I bet you have. And I also bet that you are often tempted to order more than you normally would.

It can be one of those awkward moments. You passed on starters, chose the ladies fillet and went halvies on dessert. Only to have Tapeworm Tim down the other end holler, "Hey – let’s just split the bill?"


It does make perfect sense; for every extra R1, you only pay R1 x 1/N (where N is the number of people at your table). But it is a fundamentally flawed system (except for the culprit), as they alone get the benefit of the food and everyone shares the cost.

It is known as “Aidan’s Rule”. Or as economists call it - The Diner's Dilemma.

The Economic Journal published a paper entitled The Inefficiency of Splitting the Bill (pdf), in which the authors consider what they call the unscrupulous diner's dilemma. Diner's Dilemma occurs when diners aim to obtain the highest reward but ultimately end up in an unfavourable position. Since the cost of the meal will be divided equally, most diners will order more expensive dishes, but they actually end up paying a more expensive bill than they intended.

They set up three scenarios for a group of six diners: 1) paying individually, 2) splitting the bill equally, and 3) receiving a free meal. Predictably, the average bill is smallest in the first case, with diners ordering 1.67 dishes on average. When splitting the bill equally however, sees the average meal cost increasing by 36%. The most gluttonous behaviour is observed in the free meal scenario, where participants ordered 3 dishes on average and the meal cost increased a whopping 220%.

So what do you do?
Pay What You Had
Paying for what you owe seems the fairest option, but rarely works out. All of a sudden basic maths is escapes most. People forget what they ordered, and basic math becomes conveniently difficult. Often you end up with too little money on the table to pay the bill and leave a proper tip.

Ask for Separate Bills
Asking for separate bills is the most equitable way to split the tab because each person pays for their share of the bill. Most restaurants do not allow this though.

Take Turns Paying
This can work for those who frequently dine out together and generally eat at restaurants with similar prices. The bill-paying process is quick and simple.

Split the Bill Evenly
No explanation required. Just make sure you order items approximately equivalent in price, and that no one has a problem to splitting the bill.

Credit Card Roulette
Put everyone’s credit card in a hat and pick one; that person pays the check. It’s simple, and with the right crowd, it makes for a good laugh.

In the end, it doesn’t really matter. Sharing a meal with mates is supposed to bring you together, over good food and conversation. Someone always forgets how many beers he had, or those that don’t put in enough for the tip. Why spoil a great dinner quibbling over who ordered an extra Dom Pedro?

If all else fails – just order the Lagavulin 16 Year Old. Double?  Yes, please.

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