Information Systems and Economics prof. ✡️ AP @ChapmanArgyros ML @workhelix

Los Angeles, CA
Joined November 2008
Turns out agents are just like grad students: If you give them an impossible task they will go insane trying to achieve it. paradigm3.org/research/opena…
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Jonathan Hersh retweeted
A good canary in the coal mine for AI-caused job loss will be call centers. We're currently projecting ~2.75M call center jobs in the US in 2026. In 2016 it was ~2.63M. The global call center market size has grown ~35% in that time period (from $298B to $405B). Peak employment was 2019 at ~2.98M. When we see a -50% employment drop in this sector you can get ready for broad disruption across the economy.
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Jonathan Hersh retweeted
There has been a lot of warranted discourse about California's pro-housing laws underperforming, but in cities where YIMBYs have organized, shifted local politics, and won elections, the last 10 years have seen an absolute sea change in permitting.
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Am I the dog or is ChatGPT?
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Jonathan Hersh retweeted
Do you support or oppose new AI data centers being built in your local community? 31% support, 44% oppose Would you support or oppose new data centers if they lowered your property taxes by 10%? 59% support 18% oppose
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Jonathan Hersh retweeted
When you ask Americans whether they are optimistic or pessimistic about AI, optimism beats pessimism by ~5 points. The primary fault lines are age, gender, and race - young people, men, and racial minorities are the most optimistic about AI. N=30,900 , fielded 12/1 to 12/10
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Jonathan Hersh retweeted
Christians in Bethlehem 1922-2025 1922-1945 The earliest data point is taken directly the British Mandate census from ‘22 for the town, which shows 6,658 residents with 5,838 Christians, 818 Muslims, so 87.7% Christian (1). By ‘45 the same Mandate census show a drop to 73% with 8,820 inhabitants: 6,430 Christians and 2,370 Muslims (2). 1967-1995 Immediately after the 1967 Six-Day War, Israel conducted a full census with the ICBS supervising and publishing this as “Census of Population 1967: West Bank of Jordan, Gaza Strip, North Sinai and Golan Heights”, in several volumes, with detailed tabulations by locality, religion, sex, and other variables. The Levy Economics Institute digitized these volumes which constitute the first modern census reports, (4). For an easily accessible summation for Bethlehem, the The Jewish Virtual Library’s Bethlehem page states: “In the 1967 census taken by Israel authorities, the town of Bethlehem proper numbered 14,439 inhabitants, its 7,790 Muslim inhabitants represented 53.9% of the population, while the Christians of various denominations numbered 6,231 or 46.1%.” (4,5) The number of Christians in Bethlehem enjoyed a period of relative stability between ‘67 and ‘95, when under Oslo II, against local Christian pleas to Rabin’s government opposing the move, the area was handed over to Palestinian Authority control. PCBS 1997 census gives Bethlehem city between 21.7–21.9k people but no religion based breakdown; PCPSR/Philos and church sources converge on “about 40% Christian in 1998” (6,7). This implies c. 8.5–9k Christians, i.e. low-40s percent. For 1995 I would put the number at closer to the 45% mark on overall trend, but this is not a precise figure and I have to dig further to see if this portion of my graph and claim can be better anchored. What is repeatedly cited is 40% by 1997-8 across multiple Christian and Palestinian sources. Still, even at 40% the number of Christians translates to about 8,800, an increase from 1967’s 6,231. Note that PCBS uses “urban Bethlehem” for the tri-cluster of Bethlehem, Beit Jala and Beit Sahour plus their municipal boundaries but disaggregates from rural villages and the three refugee camps, Aida, Azza, and Dheisheh. Later ARIJ work cites the 1997 census, giving the “urban Bethlehem” population as 44,880, which is just the sum of those three municipalities in the 1997 tables. But in the Bethlehem-row of that locality table PCBS records a population of just under 22,000 as cited above. 2007-2025 The 2007 data point rests primarily on the PCPSR/Philos reconstruction of Christian demography in the occupied Palestinian territories. Using PCBS census data and its own fieldwork with local councils and churches, PCPSR notes that Bethlehem’s Christian share fell to 28% by 2007, with Christians declining to only 1.2% of the total Palestinian population but remaining concentrated in Bethlehem and a few other towns. The National Catholic Reporter piece from December 2016 quotes mayor Vera Baboun that “by 2016, the Christian population dipped to just 12 percent” in Bethlehem and its surrounding villages and that “today there are just 11,000 Christians” in Bethlehem. Friends of the Holy Land’s 2018 gathering report states 18% for Bethlehem’s Christian share. Lee’s AIJAC article in early 2019 uses a comparable framing, noting that since the PA took over the city in 1995 “the Christian percentage of the city’s population has plummeted from 40 per cent to 12 per cent,” and that the city’s population of c. 27,000 in 2017 was 23% higher than in 1998. A Reuters 2024 Christmas piece about Bethlehem picks up those same threads, stating that “as of a 2017 census, the overall population of Bethlehem was 215,514 with only 23,000 Christians among them,” and infers a Christian share “around 10%” in Bethlehem city. PCBS’s 2021 projected mid-year population tables by locality have Bethlehem total city pop’n rising from 28,343 in 2017 to c. 33k by 2025.
2.6 billion people around the globe are about to celebrate the birth of a Jewish man in Bethlehem of Judea 2000+ years ago, but some people still don’t think any Jews lived there before 1948.
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Why won't AI let me be confidently wrong?
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Jonathan Hersh retweeted
How did people in 1913 see the world? How did they think about the future? We trained LLMs exclusively on pre-1913 texts—no Wikipedia, no 20/20. The model literally doesn't know WWI happened. Announcing the Ranke-4B family of models. Coming soon: github.com/DGoettlich/histor…
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California builds basically no condos. This is a real problem, as their starter homes of 2025. Here's what I've learned as to why. (1/n)
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Why can’t we have nice things??
A proposal to build 790 apartments on the site of a Safeway and surface parking lot in San Francisco’s Marina district would more than double the size of the grocery store. Naturally, the mayor, the district supervisor, and many nearby residents oppose it.
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Wait, there has to be a catch. 1000 new housing units AND a bigger grocery store? It’s almost like there’s a third dimension here to exploit.
This project is awesome. It would turn an old single-story Safeway grocery store into an iconic mixed use gem. Check out these stats: - 790 new housing units (86 affordable) - 88 studios - 132 two-bedroom units - 85 three-bedroom units (!!!) - 50% larger Safeway on ground floor
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I knew that townhouses were a big part of the Auckland YIMBY success story, but I didn't realize that they're basically the entire story.
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Jonathan Hersh retweeted
Montgomery County, MD, (one of nation's most affluent counties) enacted rent control in July 2024. Watch how multifamily building permits evaporated. Poof. Meanwhile, the rest of Maryland held steady on permits. Incredibly effective NIMBY-ism.
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You mathmatically can't compound your way to wealth anymore... 20 years, 7% returns, 3% inflation, 40% taxes -- best case you 1.5x your investment. That is why the kids YOLO it... plain and simple.
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Jonathan Hersh retweeted
Literally every real estate expert said this would happen. No one who knows anything about housing is surprised by the results. Lawsuits against the software are smokescreens and feints so that NIMBY and progressive politicians don’t have to talk about supply. Remember— if you are not talking about supply you are not really talking about housing affordability!
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I really need a data analyst job based in SF. I know SQL well + some Python. I’ve done a variety of types of data analytics over the course of my career but my primary experience is in RevOps/BI. If you can’t hire me, could you please RT for visibility? linkedin.com/in/adomalewski?…
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Jonathan Hersh retweeted
This is a good illustration of a general principle: As you build new high-end apartments, people move up, freeing up supply of lower-tier apartments. Building luxury housing thus lowers downmarket rents. You don't need to build 'affordable housing' to make housing affordable.
Here's something fascinating happening in the apartment market right now. The cheapest, oldest apartments (Class C) are getting crushed right now. But ONLY in cities that just delivered tons of new apartments. Let me show you the numbers: Denver: Class C rents down 13.9% Naples: Class C rents down 13.5% Austin: Class C rents down 13.3% Phoenix: Class C rents down 10.5% San Antonio: Class C rents down 7.2% Dallas: Class C rents down 6.5% What do all these cities have in common? They just absorbed a massive wave of new apartments. But here's the twist... In cities that DIDN'T get a big supply wave? Class C rents are actually RISING. 20 cities saw Class C rents go UP more than 3%. 19 of those 20 cities had supply BELOW the national average. So what's going on? It's basically musical chairs. When a brand new luxury apartment opens up, where do those renters come from? They don't appear out of thin air. They move from slightly older apartments. Those apartments now have vacancies. So they drop their rents to compete. That pulls in renters from even older apartments. And down the chain it goes. Eventually it hits the oldest, cheapest apartments at the bottom. And here's why they get hit the hardest: People living in Class C apartments are already spending a huge chunk of their paycheck on rent. To fill empty units, landlords have to cut prices A LOT. Sometimes enough to attract people who couldn't afford market-rate apartments before. It's like a waterfall effect. The water (new supply) at the top pushes everything down. But here's the important part: This proves that building new apartments - even "luxury" ones - reduces rents all the way down the spectrum. If it was just an affordability crisis, you'd see Class C rents falling everywhere. In high-supply cities AND low-supply cities. But we're not seeing that. We're seeing a perfect split: Lots of new apartments = falling Class C rents Few new apartments = rising Class C rents New supply at the top creates relief at the bottom. Also: wages have been growing faster than rents for 3 straight years. More people can afford apartments today than before. The bottom line? This is what happens when you actually build housing. Supply works. (Chart and analysis from Jay Parsons - one of the sharpest real estate economists out there)
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Jonathan Hersh retweeted
So you’re telling me that “luxury” apartments are driving down the costs of naturally affordable apartments because there are less folks competing for a small pool of housing stock!? Luxury housing is good for affordability!? EUREKA!!!!
Here's something fascinating happening in the apartment market right now. The cheapest, oldest apartments (Class C) are getting crushed right now. But ONLY in cities that just delivered tons of new apartments. Let me show you the numbers: Denver: Class C rents down 13.9% Naples: Class C rents down 13.5% Austin: Class C rents down 13.3% Phoenix: Class C rents down 10.5% San Antonio: Class C rents down 7.2% Dallas: Class C rents down 6.5% What do all these cities have in common? They just absorbed a massive wave of new apartments. But here's the twist... In cities that DIDN'T get a big supply wave? Class C rents are actually RISING. 20 cities saw Class C rents go UP more than 3%. 19 of those 20 cities had supply BELOW the national average. So what's going on? It's basically musical chairs. When a brand new luxury apartment opens up, where do those renters come from? They don't appear out of thin air. They move from slightly older apartments. Those apartments now have vacancies. So they drop their rents to compete. That pulls in renters from even older apartments. And down the chain it goes. Eventually it hits the oldest, cheapest apartments at the bottom. And here's why they get hit the hardest: People living in Class C apartments are already spending a huge chunk of their paycheck on rent. To fill empty units, landlords have to cut prices A LOT. Sometimes enough to attract people who couldn't afford market-rate apartments before. It's like a waterfall effect. The water (new supply) at the top pushes everything down. But here's the important part: This proves that building new apartments - even "luxury" ones - reduces rents all the way down the spectrum. If it was just an affordability crisis, you'd see Class C rents falling everywhere. In high-supply cities AND low-supply cities. But we're not seeing that. We're seeing a perfect split: Lots of new apartments = falling Class C rents Few new apartments = rising Class C rents New supply at the top creates relief at the bottom. Also: wages have been growing faster than rents for 3 straight years. More people can afford apartments today than before. The bottom line? This is what happens when you actually build housing. Supply works. (Chart and analysis from Jay Parsons - one of the sharpest real estate economists out there)
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Jonathan Hersh retweeted
13/ No one wants aggregate income to fall, so how do we build more housing? How do we get more cities into the "Wealthy & Affordable City Zone"?
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