Annual Review of Restaurant Sharing Math
Someone suggests sharing a dish partly because portions are enough and partly because prices are not.
What Would Have Happened If No One Had Suggested Sharing
The subject would have ordered the prawn curry. The friend would have ordered the chicken. Both dishes would have arrived at the table. Both would have been eaten individually, which is the standard use case for dishes at restaurants.
The bill would have come. The bill would have been split. Total spend per person: approximately five hundred and forty rupees, which is within the range of what restaurants in this city charge for a meal in 2022, which is a range that diverges from what restaurants in this city charged in 2019, which is when both parties developed their baseline expectations.
Nobody would have mentioned the price.
What Actually Happened
The subject looked at the menu. The subject noted that the prawn curry was three hundred and eighty rupees. The subject recalled that the prawn curry at this restaurant was previously two hundred and ninety. This calculation happened without effort. The old price is not stored anywhere. It was just there.
The subject said: "Should we share one of these?"
The suggestion was received as practical. Portions are generous. Sharing is common. The suggestion was accepted immediately.
Nobody mentioned the price.
The Investigation
The purchase is ordinary, yet each price now feels like evidence in a private economic investigation that both people are running simultaneously without having agreed to run it. The investigation does not need to be discussed. It informs behavior instead.
Every remembered old price remains legally active as a comparison point until the buyer stops mentioning it. The subject has not mentioned the old price. The old price is still in effect.
The Sharing Mathematics
Half the prawn curry: one hundred and ninety rupees plus sharing protocol overhead, which is the social work of dividing one dish designed for individual consumption across two people who have different appetites and different ideal ratios of rice to curry. The overhead was managed without comment.
The meal was good. The portion was adequate for the reduced cost. Both parties left satisfied.
The First Consequence
The first case of restaurant sharing math changes one small decision without being discussed. One person scans prices before speaking. The scan is not announced.
The Second Consequence
After repetition, the two people now default to sharing one main and ordering one each of the others. The default was not negotiated. It arrived through repetition and was noticed only when one party went to dinner with someone else and found themselves scanning the menu differently.
The Third Consequence
Eventually restaurant sharing math acquires an unwritten enforcement system that everyone denies creating. A third person joins a future dinner. The third person orders without calculation. This is observed with a species of respect.
The Honest Account
The sharing was partly practical. The portions were genuinely enough. The old price was two hundred and ninety rupees and the investigation found the difference relevant and continues to find it relevant, and will find it relevant until either the price comes down or the old price is forgotten, and the old price is not being forgotten.