A Michigan man filed a lawsuit against AMC Theaters challenging the legality of the chain's policy prohibiting moviegoers from bringing outside food and beverages into the theater — a policy that, in his view, amounted to forcing captive consumers to pay inflated prices for concessions they had no choice but to purchase if they wanted to eat during a film.

The case tapped into a widespread and legitimate frustration. Movie theater concession pricing operates on a model that bears little relationship to the actual cost of goods. A large popcorn that might cost $1.50 to produce is sold for $7 or $8. A bottle of water, available for under a dollar virtually everywhere else, costs $4 at the concession stand. These margins exist because the theater has a captive audience and a monopoly on in-venue consumption.

The lawsuit's legal theory focused on consumer protection statutes — the argument that the combination of outside-food bans and premium pricing constituted unfair or deceptive trade practices. Legal experts were skeptical: courts have generally held that businesses have wide latitude in setting their own policies, including what may or may not be brought onto their premises.

The economics of movie theaters are genuinely unusual. Studios take a substantial portion of ticket revenue, particularly in the early weeks of a film's run. Concessions are where theaters actually make money — they are, in a real sense, snack businesses that also show films. Without concession revenue at current margins, the economics of theatrical exhibition become very challenging.

None of which makes a $8 popcorn feel more justified. But it does explain why theaters have little incentive to change without legal or competitive pressure.