DAN ARIELY

Update On “Procrastination, Deadlines, and Performance: Self-Control by Precommitment” (2002) by Dan Ariely and Klaus Wertenbroch

Aug. 7, 2026

As a social scientist, I am hardwired to believe that when evidence underlying a hypothesis or
conclusion changes, it is critical that the record be updated to reflect those changes, both as a
means of preserving integrity and facilitating the pursuit of truth.

Recently, I was made aware that data underlying a 2002 paper about deadlines and
procrastination that I co-authored contained serious anomalies that suggest deliberate
tampering.

I don’t intend to argue otherwise – the documentary record available to me today, more than 20
years later, isn’t sufficient to answer the questions that have been raised. Moving forward, my
responsibility as co-author lies in supporting efforts to establish, to the greatest extent possible,
a complete and accurate account of the events.