2026-03-18 02:38:53
South Africa holds the grim distinction of being the most unequal country on Earth. South Africa leads the global ranking with a Gini index of 0.63. Statista The richest 10% of South Africans hold 71% of the wealth, while the poorest 60% hold just 7%. World Population Review This extreme inequality is largely rooted in history — economists attribute it to historical land ownership laws, the lingering socio-economic impacts of apartheid, and an economy heavily reliant on undiversified natural resource extraction. Data Pandas
The World (Global Gini) is trickier to pin down, because it measures inequality across all of humanity rather than within a single country. Different scholars estimate the global Gini index to range between 0.61 and 0.68. Wikipedia Interestingly, when measured this way — treating every person on Earth as part of one big “country” — global inequality ends up being comparable to South Africa’s, because the gap between the world’s richest and poorest nations is enormous.
That is from Claude.
The post One reason why South Africa is difficult to govern (South Africa fact of the day) appeared first on Marginal REVOLUTION.
2026-03-18 02:17:11
It seems execution beats foresight:
Retail traders correctly forecast asset price direction yet lose money. Using 222 million prediction market trades with observable terminal payoffs, we decompose returns into a directional component (did the trader pick the right side?) and an execution component (did the trader get a favorable price?). Traders with above-random accuracy earn negative returns because they arrive late and pay unfavorable prices; traders with near-random accuracy profit through superior execution. These two dimensions of skill are nearly orthogonal (ρ ≈ 0.13), and split-sample tests confirm both are persistent. What separates profitable from unprofitable traders is not forecasting ability but execution: automated traders pay 2.52 cents less per contract than casual traders, and this gap alone accounts for the sign of returns across trader types. Being right and making money are not the same thing.
That is from Joshua Della Vedova. Via John de Palma.
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2026-03-18 00:43:03
Live in Cape Town long enough and you lose interest in the outside world. Visitors from more exciting cities start yawning at your dinner table, but I no longer care. They have no possible conception of the unbearable bliss of fine summer days when the sea is warm and the figs are ripe and you start the morning with a dive into a cool green rock pool, followed perhaps by coffee in one of those impossibly quaint cafes and a spot of light typing, if I can manage to ignore the drama outside my window – tides rising, whales blowing, birds diving, the boats coming back to Kalk Bay. The Contessa and I often walk down to meet them, come home with a fat Cape salmon or snoek. Come sundown, we set the fish to grill on an open fire, uncork a bottle of wine, and, yes, congratulate ourselves for living in the last corner of Africa that is immune to chaos and madness.
The post Rich Elliott on Cape Town (from my email) appeared first on Marginal REVOLUTION.
2026-03-17 21:44:57
1. “Absolutely astounding figures from the NY state comptroller: spending on services for the NYC street homeless population ran to $81,705 per person last year, up from $28,428 pp 6yrs ago. Figures do not include all kinds of other spending, supportive housing, policing costs etc.” Link here.
2. Backlash against The Giving Pledge (NYT).
3. Poor weather when touring a college campus reduces a student’s chance of applying.
4. Where do AI agents settle their payments?
5. Even Nevada never had that much of a real estate bubble?
6. Prediction markets turn many people into unwilling referees. Good and interesting piece.
7. GPT Pro on the value of introspection. “The literature does not really say “successful people are introspective.” It says: successful people are better at turning reflection into accurate self-insight, external calibration, and better next actions.”
NB: The passing of Coetzee is now not confirmed.
The post Tuesday assorted links appeared first on Marginal REVOLUTION.
2026-03-17 15:01:49
That is the topic of my latest column for The Free Press, here is the closing tag:
The biggest risk is not from the AI companies, but rather that the government with the most powerful AI systems becomes the bad guy itself. The U.S., on the world stage, is not always a force for good, and we might become worse to the extent we can act without constraint. The Vietnam War is perhaps the least politically controversial way of demonstrating that point.
So today we need an odd and complex mix of not entirely consistent ideologies for the current arms race to go well. How about some tech accelerationism mixed with capitalism, and then a prudent technocratic approach to military procurement, to make sure those advances serve national security ends? On the precautionary side, we need a dash of the 1960s and ’70s New Left and libertarian anti-war ideologies, skeptical of Uncle Sam himself. We do not want to become the bad guys.
Do you think we can pull that off? The new American challenge is underway.
Worth a ponder.
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2026-03-17 12:57:28
Average grades continue to rise in the United States, raising the question of how grade inflation impacts students. We provide comprehensive evidence on how teacher grading practices affect students’ long-run success. Using administrative high school data from Los Angeles and from Maryland that is linked to postsecondary and earnings records, we develop and validate two teacher-level measures of grade inflation: one measuring average grade inflation and another measuring a teacher’s propensity to give a passing grade. These measures of grade inflation are distinct from teacher value-added, with grade inflating teachers having moderately lower cognitive value-added and slightly higher noncognitive value-added. These twomeasuresalso differentially impact students’ long-term outcomes. Being assigned a higher average grade inflating teacher reduces a student’s future test scores, the likelihood of graduating from high school, college enrollment, and ultimately earnings. In contrast, passing grade inflation reduces the likelihood of being held back and increases high school graduation, with limited long-run effects. The cumulative impact is economically significant: a teacher with one standard deviation higher average grade inflation reduces the present discounted value of lifetime earnings of their students by $213,872 per year.
That is from a recent paper by Jeffrey T. Denning, Rachel Nesbit, Nolan Pope, and Merrill Warnick. Via Séb Krier.
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