The Lindy Commitment Test
However long you've sustained something is roughly how much longer you can trust it to last.
- Difficulty
- Starter
- Time to result
- ~days to results
- Steps
- 3
- Confidence
- 85%
A persistence-decision mental model: to judge whether to keep going on a hard, open-ended commitment, project its future lifespan as at least equal to how long you've already sustained it. Use it at the wobbly point where you're deciding whether a grind is worth continuing.
Origin
Nine months into writing a weekly newsletter, Lenny hit a moment of doubt and applied the Lindy effect (a concept popularized by Nassim Taleb: for non-perishable things, life expectancy grows with age). He reasoned that since he'd sustained it for 9 months, he could probably do 9 more — which gave him permission to keep going and add a paywall.
Core principles
- 01For non-perishable habits and projects, the longer it's already run, the longer it will likely continue.
- 02Use elapsed consistency as evidence of future capacity, not as sunk cost.
- 03Reframe 'can I keep this up?' into 'I've already proven I can, for at least this long again.'
How to run it
- 1
Measure your sustained streak
Count how long you've actually kept the commitment going consistently — the real elapsed track record, not intentions.
Watch out Only applies to Lindy-type things (habits, ideas, projects) — not perishable things that decay with age.
- 2
Project an equal runway forward
Assume you can sustain it for at least that same duration again, and let that reframe the doubt into a manageable horizon.
Pro tip Pair it with your backlog: Lenny noted he still had 'all these ideas and things I want to write about,' which reinforced the projection.
- 3
Commit within that horizon
Make the next big decision (invest more, monetize, keep shipping) inside the projected window rather than agonizing over 'forever.'
In the wild
Lenny realized he'd published weekly for 9 months, so via Lindy he could 'probably do this for at least probably another year.' That confidence is when he added the paywall and started charging.
→ The paywall worked — 'meaningful dollars like a month in' — validating the continued commitment.
On the podcast Michelle applies it playfully: 7 years since the 2019 newsletter start implies at least 7 more. Lenny accepts the frame: 'Okay. So, we got 7 years. I could do that.'
→ Turns an unanswerable 'where does this go long term?' anxiety into a bounded, acceptable horizon.
Common mistakes
Applying it to perishable things
Lindy only holds for non-perishables (ideas, habits, technologies). Using it on things that decay with age gives the opposite, wrong conclusion.
Treating the streak as sunk cost
The point is forward-looking evidence of capacity, not a guilt-driven reason to continue something you no longer want.
Is it for you?
Best for
Solo creators and founders wavering on whether to continue an open-ended weekly commitment.
Not ideal for
Decaying assets, dying markets, or commitments where the streak masks genuine burnout.
From the transcript
“there's this concept of a thing something being Lindy, which is uh as long as it's been going for, it will most likely last at…”
“I've been doing this every week for 9 months.”
“Which means I could probably do this for 9 more months.”
From the episode
How I built a 1M+ subscriber newsletter and top 10 tech podcast
Lenny Rachitsky