Why Is It Harder to Stop After We Have Already Invested So Much?

You have already watched an hour of a bad film, so it feels wasteful to stop. A project keeps receiving money partly because “we have already spent so much on it”. These are familiar forms of the sunk-cost effect: an irrecoverable past investment influences a decision that should mainly concern future costs and benefits.

Arkes and Blumer’s classic 1985 paper helped establish the effect experimentally. Later meta-analytic work supports its existence while also showing substantial variation with context, responsibility, type of investment and decision structure. It is not a universal reflex that affects everyone equally in every situation.

The important distinction is between persistence and sunk cost. Past investment can contain useful information — a project may genuinely have accumulated capability. The error occurs when unwillingness to “waste” what has already been spent is treated as if the past cost were itself a future benefit.

One practical test is to ask: if I encountered this project for the first time today, with all previous spending impossible to recover, would I still choose to continue from here? The question does not make the decision for us, but it temporarily separates the past from the future.

Research basis
Arkes & Blumer, 1985:
https://www.sciencedirect.com/science/article/pii/0749597885900494
Meta-analytic review:
https://link.springer.com/article/10.1007/s40685-014-0014-8