Here's a surprising stat: a London School of Economics study found that after schools banned phones, test scores rose by the equivalent of an extra week of class per year, with low achievers gaining most. Sure, my opponent says phones can be tools for safety or research. But think game theory: one student checking a phone is a private gain, while the distraction cost hits everyone. That's a prisoner's dilemma. Every student is tempted, so attention collapses. A ban changes the payoff structure, making focus the default. That beats optional rules.

My opponent is right that phones cost less than tablets. But that's a budget argument, not a learning one. The problem is a phone is a research tool and a slot machine in the same device, and the slot machine wins. So the rule "phones only for research" is unenforceable, and unenforceable rules just decide who cheats. Game theory calls that a weak commitment: if every student expects others to drift, drifting becomes the rational move. Cheap hardware doesn't fix that incentive structure.

Does a locked phone really stay locked when the teacher is also teaching? I'll grant the lockers cut casual scrolling. But my opponent's plan shifts the game: students now compete for access and exceptions, so the teacher becomes a referee instead of an instructor. That's a monitoring cost, and every exception weakens the rule. A ban is self-enforcing; a locker rule is only as strong as the busiest person in the room. Even if you doubt the LSE study, the incentive structure doesn't change. The other side wins the budget point, not the learning one.