Zohran Mamdani has been one of the most controversial New York City mayoral candidates in years. No other candidate, not even Bill DiBlasio, has had such liberal views. As such, many people are of the belief that thousands of people, particularly the very rich are fleeing New York City and thousands are moving to Greenwich to avoid what are said to be confiscatory tax increases, but what do the numbers actually say?
House sales are up slightly
The first part of the above statement is easy to disprove. So far this year, we have sold 424 single family homes, which annualized gets us to only 519 house sales by year end. The biggest year we ever had for house sales was 2021 when we had 1,006 sales. Our 20-year average for sales is 655 houses per year. Based on this our sales for 2025 are going to be below average, though they will be slightly above the 501 houses we sold in 2024. We can’t have thousands of people buying houses in Greenwich, there aren’t enough to buy, but more that later.
Rentals are up slightly
But what about rentals? All those NYC refugees must be renting until they can buy. We always have more rentals than sales in Greenwich. So far this year, we have had 672 closed rentals on the Greenwich MLS or annualized we are expecting around 806 rentals. These 806 rentals, like house sales, are up from last year’s 750 rentals. In fact, if we have 806 rentals on the Greenwich MLS, we will be pretty close to our 25-year average of 820 rentals. Under $3,000/month we do have a fair number of private rentals, but it’s not in the thousands and those tenants are generally not high net worth tenants.
But, we could have a lot more condo sales
So far in 2025, we have sold 140 condos and co-ops in Greenwich, which annualized is 170 condos. This compares to our 20-year average of 187 condos sold on the Greenwich MLS and our 193 condo sales last year. While house sales and rentals are up a little, condo sales are actually down in 2025, even as inventory is up, so these Mamdani refugees are not buying very many condos.
What about private transactions?
Last year 93 house sales or 19.4% of house sales were not listed on the Greenwich MLS, i.e. were private sales. It’s possible that private sales have gone up, I haven’t written an analysis of our private sales in 2025, (which means that’s what I’ll do next week). Based on the private sales I have seen the market is busy, but no busier than last year, nor has the number of off-market sales expanded hugely this year.
Low Inventory hides any Mamdani effect under $5 million
Based on the above, you could conclude that there is no Mamdani effect, but I think that is wrong. You just have to look in the right places. The Mamdani effect, to the extent we have it, under $5 million is suppressed by our lack of inventory. At the end of Q3 2025, our single-family home inventory was only 116 listings or down 28% from last year and down over 80% from 2019.
We’ve had a tight market all year as what inventory that comes on, if priced right, goes to contract quickly. In October, we had an anemic fall market for new inventory. While lots of people may be fleeing NYC before Mamdani is likely elected next week, they are going to find very little to buy in Greenwich.
Is Mamdani driving contracts up in Greenwich?
You could make a case that we can see the Mamdani effect in the number of contracts that have been signed in the last five week. We have had 70 contracts signed in the last five weeks, which is remarkable. Even with much lower inventory, our number of contracts has actually exceeded last year While the rise is dramatic, the actual numbers are not that big. In 2024, we had 53 contracts signed in the same period or in other words, we have 17 more contracts signed in the same period in 2025. This is by no means a rush to Greenwich, but a deeper look does show, what I believe is a Mamdani effect. What you want to look at is the prices of those houses that were going to contract.
Mamdani may be driving high-end sales in Greenwich Greenwich is having our best year ever for high-end sales. Through the 3rd quarter our sales over $5 million are up 43%, while sales over $10 million are up 100%. When you look at this over the last 26 years (which is as far as our GMLS data goes back), the jump in this year’s sales number and sales volume is dramatic. In October this pace accelerated. We are on track to have a 121% more sales over $10 million in 2025. Our previous record sales year was in 2007 where we had “only” 19 sales compared to an estimated 42 sales this year.
To see the Mamdani effect you want to look at contract dates, since the actual sales date could be months after the buyer agreed to buy. Mamdani won the Democratic primary on June 25th. Prior to that date we had had 17 contracts signed for properties listed over $10 million this year. After June 25th, we have had 21 contracts signed. So far this year, 29 of the contracts have closed at a median of 95% of their original list price. With 9 of those 29 sales being for full list price or in two cases over list price.
This is a slight bump up, from 17 contracts to 21 contract post-nomination but if adjust for the number of days pre- and post- Mamdani nominations the effect is even bigger. We had a 176 days to sell 17 ultra-high-end listings pre-nomination. Post-nomination, we have had only 125 days to sell 21 listings. Post Mamdani’s nomination, high end houses are selling 74% faster.
The place where we really see the effect is when you look at total sales dollars. The 17 ultra-high-end, pre-nomination sales totaled $251 million or an average of $14.8 million. Post-nomination sales totaled $407 million or an average of $19.4 million per house. Not only did we have more sales in a shorter period post-nomination, but the average sale was for $4.6 million more.
We also saw our highest contracts after Zohran Mamdani’s nomination. A sale for $43.5 million was signed on July 28 and closed on August 25. Another property listed at $43 million went to contract on August 21.
How big is the Mamdani effect?
Looked at one way the Mamdani effect is only 36 additional sales and contracts over $5 million in 2025 compared to 2024. The problem is those families pay a lot of taxes to New York City and New York State. A $40,000 increased SALT exemption means little to the folks in these price ranges. Also, Greenwich is only one town of 63,000 people. From what I hear, other areas are seeing similar high-end sales spurts.
Some of these towns that are seeing a jump in high-end sales are in the New York metro area, but some aren’t. A bigger factor driving record high-end sales in Greenwich, and other areas, is probably the run-up in the stock market. Many people are sitting on a lot of paper profits. Some of them are worried that the market may not do as well next year, so investing in high-end real estate looks like a good way to reduce their market exposure. Also, the dollar is down against many currencies, and the U.S. is getting cheaper.
New York City is the engine that drives this area, and we all need it to do well, but you can only tax so much, before people change their tax domicile or even leave the City entirely. The fear of these changes makes some people change their domicile. We saw a similar effect in 2013 when Bill de Blasio was elected. Interestingly, that year, it was buy the rumor and hold the fact. We saw a distinct jump in sales after de Blasio was nominated but once elected there were no more contracts signed over $10 million.
Stay tuned the next couple of weeks are going to be interesting.
