The Prisoner's Dilemma of Pregames

For many UVA students, a night out starts with a pregame at a friend’s apartment, progresses to one of the corner’s finest establishments, winds down with cheap food, and ends with a collapse into bed followed by a morning filled with regret. 

As rational economic actors, students seek to have as much fun as possible while minimizing costs associated with their fun. To that end, many attempt to consume their chosen quantity of alcohol (a driver of fun for many) at pregames, where it is free and accessible, as opposed to at a bar, where it is expensive in dollars and time. In fact, according to an alcohol.org survey, the top two reasons for pregaming were to have more fun, and to save money. However, many pregame planners underestimate their guests’ thirst, so the alcohol at a given pregame is scarce. Therefore, between incentives to consume as much alcohol as quickly as possible, and the results of doing so, a prisoner’s dilemma appears between two groups at a pregame that we will call “first years” and “fourth years”.

First Years\Fourth Years	Imbibe Moderately	Imbibe Aggressively
Imbibe Moderately	19\ 7	1 \ 10
Imbibe Aggressively	21 \ 1	3 \ 3

Each group has two choices: imbibe moderately, or imbibe aggressively. If both groups follow their dominant strategy to imbibe aggressively, things go poorly (3 \ 3): they get their free, accessible alcohol, but the pregame ends far earlier than most prefer to leave for the corner. Other negative consequences of drinking too much too fast aside, the first years will return to their dorms early and be written up by the RA on coverage, and the fourth years will go to a friend’s lawn room and drunkenly discuss how unprepared for adulthood they are. Yikes. 

If either group imbibes aggressively while the other one imbibes moderately (22 \ 1) (1 \ 10), the pregame lasts an appropriate amount of time, and the aggressive group consumes most of the available alcohol. The aggressive group has a great night: they pay nothing, and have a wild time on the corner. However, the other group is left with the perceived worst possible outcome: they pay to consume in a bar, or (in what is probably the healthiest outcome) don’t consume any more alcohol for the rest of the night.

 If both groups imbibe moderately, the pregame turns out great, and maximizes total utility(19 \ 7): everyone has fun, plays a few games of beer pong, and leaves for the corner at an appropriate time, just when the last can of Bud Light® is consumed. Players will be close to their optimal level of drunkenness, and will gain additional utility from homogeneous levels of intoxication across both groups.

Given these strategies and outcomes, the pregame planner can act as the “government” in this prisoner’s dilemma, using their control over the availability of alcohol at their pregame to limit their guests’ rate of consumption. The planner can do this through imposing negative social consequences on those who imbibe too aggressively, or by “playing bartender” and limiting the quantity of alcohol available for consumption at any one time. Though either one of these solutions incurs additional costs on the party planner, they will reap the rewards the next day through utility gained from complements on their “sick pregame”.