Surprising no one, and yet shocking many, avowed socialist Zohran Mamdani won the election yesterday to become Mayor of the largest city in the United States.[1]

Probably the main reason for Mamdani’s victory is that he pursued the tried-and-true method of giving out free stuff, and a whole generation of Americans who have systematically been poorly educated in history and economics said “that sounds awesome.” So, now we will see whether socialism will work for the first time ever.

This is an inflation blog, so I want to review briefly the effects of price controls on inflation – and indirectly, on inflation instruments. It’s interesting because we actually have some direct and recent experience with what were effectively price controls: the Biden Administration’s ‘eviction moratorium’ during COVID, that prevented landlords from tossing out renters who weren’t paying their rent. Really, it’s a pretty amazing thing that says a lot about Americans that the vast majority of renters continued to pay rent anyway.[2] An ancillary effect, though, was that landlords had no leverage to raise rents and therefore, rents stopped going up. Unsurprisingly (and here is where the lesson should have been learned), when the eviction moratorium was lifted rents re-accelerated. In the chart below, note how in 2021 effective rents declined while asking rents went up – but the red line eventually rebounded and exceeded the prior trend.

I actually haven’t looked at that chart in a little while. It’s fascinating to me that ‘asking rents’ (which come from the Census department) have maintained their divergence from ‘effective rents’ (sourced from Reis Inc). I wonder if some of that is the effect of the LA wildfires. In any case, not today’s article. The point is that the effective price controls on rents did have an effect on measured rents, but it didn’t change the economics and eventually prices caught up.

Back in 2022, I produced an excellent podcast episode entitled Ep. 37: Bad Idea of the Year – Wage and Price Controls. In it, I discussed some of the trial balloons that had been floated by the Administration and some of the really bad economics that was being used to support the idea. This is a part of the transcript (from Turboscribe.ai), and I still love the analogy:

“But the basics of how it works are very simple to visualize. Price is a teeter-totter, okay? It’s a seesaw. On one side of the seesaw sits all of the buyers. On the other side sits all of the sellers. If there are lots more buyers jumping onto one side, then the teeter-totter drops on that side, and the fulcrum, in order to make everything balance, the fulcrum has to move. And if you move the fulcrum, then you can get that to balance even with more buyers and fewer sellers.

It just means that the fulcrum, which is price, has to move in one direction. If then people, those buyers drop off, then the fulcrum moves back the other direction. If more sellers jump onto the teeter-totter, the fulcrum moves the other direction as well.

So it’s a simple way to visualize it…and yes, there are all kinds of complexities in the real world. There’s behavioral, there’s stickiness that happens, but that’s the fundamental theory of price, is what I’ve just given you, is that price is the fulcrum that balances the buyers and sellers.

So what price controls say is that, well, we don’t like where this balanced. We have too many buyers, not enough sellers, and the fulcrum has moved way over to one side and we don’t think it should be there. So we’re going to take the fulcrum and we’re going to move it to where we like it. And guess what happens? There’s no balance. All of a sudden, if you move the fulcrum away, then all of a sudden, the side with all the buyers goes down and goes thunk on the ground. There’s no balance.

“How do you then balance it? If you say that the fulcrum has to be in this location, how do you balance the teeter-totter? Well, you have to take buyers away. And you take buyers away by making a shortage. And so those buyers can’t buy anything. And then voila. So if you force the price, then the quantity has to change. And if you let both things happen, then it will magically go and balance. If it’s truly a free market and there’s good information and all that stuff.

“So does this solve the problem to push the fulcrum to one side and say, oh, there’s no inflation and to make it balanced, we shove everybody off the teeter-totter by creating a shortage? It doesn’t solve the problem. And furthermore, the people that you’ve pushed off the teeter-totter who can’t get access to the thing anymore are pretty upset. They should be upset because before they had a way to get what they wanted and what they were willing to pay for. And now they can’t because you’ve shoved them off the teeter-totter. You’ve created a shortage.”

That was a public service announcement, just to remind you why price controls don’t work. That doesn’t mean they aren’t really good politics, especially if you can leave the removal of the controls to the next guy who ‘causes’ the inflation when they come off. And it’s the politics, not the economics, that leads to this dumb idea being tried over and over despite a roughly 0% record of success.[3]

Because can price controls affect price indices? You betcha. If you make it illegal to move prices, then at least official prices will not move. So let’s consider the potential impact of Mamdani freezing rents and grocery prices, for example.

New York City is about 7% of the CPI sample. Technically, it’s New York-Newark-Jersey City but we know most of that is NYC. In the New York consumption basket, Rent of Primary Residence is about 11%, 28% is Owners’ Equivalent Rent, and 8% is Food at Home. So, if rents and grocery prices were frozen, about 19% of the NY CPI would go to zero month/month right away (at least officially – the best tomatoes will be sold on the black market for a premium of course and the best catch of the day will be sold in NJ…[4]) And since OER is based on a survey of primary rents, eventually 47% or so of the NY CPI basket will go to zero price change. I’m ignoring the quality adjustments in the housing stock, which have the effect of increasing OER inflation slightly.[5]

The effect of this on the national CPI: if 47% of the NY basket goes from, say, 4% inflation to 0%, and NY is 7% of the national CPI, then the really-rough effect on the US CPI would be 47% x -4% x 7% = -13bps per year. Obviously that’s extremely rough, but I’m just aiming for an order of magnitude calculation. 13bps is small, but noticeable. Probably not tradeable.

But here is something that’s interesting and potentially tradeable. New York City is about 30% of the Case-Shiller 10-City Home Price Index. Let’s suppose that home prices in New York over the next year drop, say, 10%.[6] That move would cause the nationwide Case-Shiller (10-city) index to drop 3%, or to rise 3% less than it otherwise would. Here’s what is interesting. The chart below shows the February 2027 NYC Metro Case-Shiller futures contract, which trades on the CME (and settles to the index for December 2026, which is released in February 2027).

There has been exactly zero price effect of the Mamdani victory. To be sure, open interest in the NYC contract – in all of the Case-Shiller contracts, for that matter – is extremely low but there is an active market-maker and the current price as I write this is 344.40 bid/351.60 offer. The last print of the S&P Cotality Case-Shiller New York Home Price NSA Index, for August 2025, was 334.08. On the bid side, then, the market is paying 3.1% higher prices than the current index. That seems sporty to me. Why would home prices rise if rents are frozen? Why would they rise if people are leaving the city?

As always, my musings here are not trade recommendations; do your own research. Disclosure: I do not currently have a position either long or short in any housing futures contract, nor does any account or fund that I or Enduring Investments manages, nor do I currently have plans to initiate any position.

[1] New York, at least for now.

[2] At the time, we worried about what would happen with the CPI since a renter paying zero rent is not skipped but the rent goes into the calculation as a zero. So you could in theory have had 10% of the basket going to zero, which would have destroyed the inflation market.

[3] If you listen to the episode: I also love my thermometer analogy.

[4] Also, though rents will stop rising the quality of the apartments will deteriorate since landlords will skimp on maintenance. Mamdani has a plan for that, though – he has said the city will order maintenance to be done and if it isn’t, the city will seize the property. Just in case there was any question who really owns any property that you can’t pick up and transport elsewhere.

[5] N.b. – the increase in the CPI nationally from the owned-housing quality adjustment almost exactly cancels the decrease from quality/hedonic adjustments in other parts of the CPI. Yet another reason that the whining about hedonic adjustment being used to ‘manipulate CPI lower’ makes no sense.

[6] You can easily make a case for a much steeper drop if the city increases property taxes to make up for declining income tax collections, not to mention if the exodus from the city looks anything like the 9% of the population who claim they’d move if Mamdani won, or if the finance industry continues to relocate to Dallas and Miami.

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