Glen's Shrine Series
Sendhil Mullainathan
Behavioral economist. MacArthur Genius. Co-author of Scarcity. Co-founder of ideas42 and J-PAL. Espresso machine restorer. The guy who gave Glen's favorite talk on Earth.
1
MacArthur Genius Grant
80+
Countries influenced by J-PAL
25
Age when MIT hired him
∞
Espresso machines restored
The Talk — Scarcity: For People Too Busy to Attend Talks
This is the one. The talk that changed how Glen thinks about time, money, and cognitive bandwidth. Non-negotiable viewing.
Why This Talk Changed Everything
I put this video on Michael Walton's page because I wanted him to watch it. I've wanted everyone I know to watch it since the first time I saw it.
Mullainathan explains something that sounds obvious but isn't: when you don't have enough of something — time, money, social connection — it literally hijacks your brain. Not metaphorically. Your IQ measurably drops. Your impulse control weakens. Your ability to plan ahead collapses.
This isn't a character flaw. It's physics. Scarcity is a cognitive tax, and it's regressive — it hits hardest the people who can least afford to pay it.
Once you understand this, you never look at poverty, busyness, or “bad decisions” the same way again.
The Core Ideas from Scarcity
The Bandwidth Tax
Scarcity of any resource (time, money, food) captures your attention so completely that it taxes your cognitive bandwidth. Poverty doesn't just mean less money — it means less mental capacity for everything else. This is why poor people make 'bad decisions.' They're not dumb. They're overloaded.
Tunneling
When you're scarce on something, you 'tunnel' — you focus intensely on the scarce thing and neglect everything else. A busy person tunnels on today's deadline and forgets to plan for next month. A broke person tunnels on rent and misses a doctor's appointment. The tunnel is the trap.
Slack
The opposite of scarcity is slack — the margin that lets you absorb mistakes. Rich people have financial slack. People with free time have schedule slack. Slack is what makes good decisions possible. Without it, one mistake cascades.
Scarcity Creates Its Own Scarcity
This is the brutal loop: being short on time makes you worse at managing time. Being short on money makes you worse at managing money. Scarcity is a self-reinforcing trap — not a character flaw.
Superpowers
Scarcity Theory
Proved that having too little of anything — time, money, social connection — literally reduces your cognitive bandwidth. Not metaphorically. Actually measurably makes you dumber at everything else.
MacArthur Genius Grant
Won the 'Genius Grant' — $500,000 no-strings-attached. The MacArthur Foundation essentially said: 'Here's half a million dollars, do whatever you want, we trust you.' That's the ultimate signal.
Institution Building
Co-founded ideas42 (applies behavioral science to real-world problems) AND co-founded the Abdul Latif Jameel Poverty Action Lab (J-PAL), which has influenced policy in 80+ countries. Built organizations that outlast papers.
Cross-Discipline Range
Economics. Machine learning. Medicine. Criminal justice. Media bias. CEO pay. Cigarette taxes. The man doesn't pick a lane — he builds highways between lanes.
Communication
Gave a talk called 'Scarcity: A Talk for People Too Busy to Attend Talks.' The title alone is a masterclass. He explains Nobel-level concepts so clearly that a non-economist (me) built him a shrine.
Espresso Machine Restoration
His listed hobby is restoring classic espresso machines. This man reverse-engineers La Marzoccos for fun. Of course he does.
Career Timeline
PhD from Harvard. Joins MIT faculty at 25.
Co-founds Abdul Latif Jameel Poverty Action Lab (J-PAL) at MIT.
Moves to Harvard as full professor.
Awarded MacArthur 'Genius Grant.'
Named World Economic Forum 'Young Global Leader.'
Co-founds ideas42 — behavioral science applied to real-world problems.
Publishes Scarcity: Why Having Too Little Means So Much with Eldar Shafir.
Named to Foreign Policy 'Top 100 Global Thinkers.'
Moves to University of Chicago Booth as Distinguished Service Fellow.
Pivots research toward machine learning in medicine and AI fairness.
The Book: Scarcity
Scarcity: Why Having Too Little Means So Much by Sendhil Mullainathan and Eldar Shafir (2013). This is the full academic treatment of the ideas in the talk. It's one of those rare books that changes how you see the world and never un-changes it. If you watched the talk and it clicked, read this.
Get it on AmazonGlen's Take
I've read hundreds of books. I've built shrine pages for billionaires and action stars and comedy legends. But if I had to pick one idea that changed how I think about the world, it's scarcity theory.
Understanding the bandwidth tax is understanding why smart people do dumb things. Why broke people stay broke. Why busy people stay busy. Why the system is rigged against the people it claims to serve.
Mullainathan didn't just write a book. He gave people a framework to stop blaming themselves and start understanding the physics of their situation. That's what a genius does.
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