Sunk Cost — the research, and how to use it at events

The research, plainly

Arkes and Blumer showed theatergoers with full-price season tickets attending more shows than discounted buyers — the money was spent either way, but the larger sunk cost pulled people to the seats. Rationally irrelevant investments keep steering behavior.

The receipt: Arkes & Blumer, 1985

What it means for events

Investment before the event is attendance insurance. Every dollar, minute, and choice an attendee sinks in advance — the paid ticket, the completed profile, the pre-work, the selected agenda — raises the odds they actually show and stay.

Where to run it

Registration design

Even a nominal paid ticket transforms show rates versus free. Skin in the game shows up.

Pre-event engagement

Profile setup, session selection, a pre-event task: sunk effort works like sunk money.

Program continuity

Multi-session programs compound investment — each attended session makes abandoning the series costlier.

Seen in the wild

The 'Concorde fallacy' gave the bias its aviation-scale nickname, but event teams meet it weekly in reverse: free-registration webinars with 30% show rates versus paid workshops at 90%. The price isn't revenue — it's commitment.

Related concepts

Commitment & ConsistencyOnce someone says it out loud — in writing, in public, by choice — they work hard to stay true to it.Endowed ProgressPeople finish what already feels started.Loss AversionLosing $100 hurts about twice as much as winning $100 feels good.

All 115 concepts in the Library →

Now use it

Score your own event against principles like this one — or make the whole vocabulary official.

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