It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Monday, December 15, 2025
New York K-12 enrollment down, but charter, homeschool rates double in a decade
ITHACA, N.Y. – New York state’s aging population isn’t only evident in more graying residents, but in a declining number of school children – down more than a quarter-million over the past decade, according to a new analysis by Cornell University demographers.
Almost 90% of the state’s school districts recorded enrollment declines from 2013-14 to 2023-24, as total K-12 enrollment dropped from roughly 3.1 million to 2.8 million students, according to the latest Topics in Demography (TiDbit) research brief released by the Cornell Program on Applied Demographics.
The decade also saw shifts in how New York youth are being educated, reflecting growth in school choice and impacts from the pandemic, researchers said. In New York City, the state’s largest district, the number of students attending traditional public schools fell by 19.1%, or about 187,000 children. That loss was offset slightly by growth in publicly funded charter schools (more than three-quarters of which are in New York City), whose enrollment statewide more than doubled to 6.5%. The share of students being homeschooled also doubled, to 1.8%, and private school enrollment ticked up slightly, to 13.6%.
Traditional public schools still outnumber others: nearly 4,700, compared with 1,800 private schools and 370 charter schools.
“An aging population is the big driver of this pattern of K-12 enrollment decline, including people having fewer children and at later ages,” said Leslie Reynolds, a research support specialist. “The loss in enrollment has been gradual over time, with some increase during Covid, but overall stemming from the larger-scale demographic change.”
The statewide graduation rate improved more than 7 percentage points, to 86.3% in 2023-24, with girls outperforming boys. Rates trailed in Big Five districts – 83.3% in New York City public schools and 74.6% across the others – and 79.6% among charter schools statewide.
Students in “low need” districts are the most likely to graduate and go on to college or other post-secondary education within 16 months. In “average need” districts, nine of 10 students graduate but a smaller share continue their educations. In “high need” urban/suburban districts, the graduation rate drops to about 77% and fewer than 6 of 10 students pursue post-secondary education.
The research brief also includes rankings showing which districts spend the biggest percentage of their budget on instruction and transportation, and which have the highest or lowest percentage of school-age children, students enrolled in private schools and learning English as a second language.
Reynolds said the research brief aims to highlight big-picture trends in K-12 education, and to prompt local districts and communities to examine how their own conditions and trajectories may vary.
But many families who are income eligible to participate in WIC aren’t receiving those benefits. Research has found that households who don’t use the full amount of their nutrition benefits are more likely to drop from the program.
New research by the University of Washington has found that households who redeem more of their benefits in the most popular food categories are more likely to remain in the program long-term. Better understanding these patterns could help WIC agencies identify families who might need a little extra encouragement to stay enrolled.
“Finding ways to identify kids and families that are at risk of dropping out of the program is of high importance,” said Pia Chaparro, a UW assistant professor of health systems and population health and first author of the study. “That’s basically what we’ve identified — a way to flag families who may be at risk of dropping off.”
WIC provides families with food benefits in specific categories, with fruits and vegetables and eggs as the most popular. In partnership with Public Health Foundation Enterprises WIC (PHFE WIC), a Southern California WIC agency with a large research and evaluation division, researchers analyzed redemption data from 188,000 participating infants and children 0-3 years old, between the years 2019 and 2023.
Among those children, higher redemption of fruits and vegetables, eggs, whole milk and infant formula was associated with lower risk of their household discontinuing WIC participation.
The risk of discontinuation decreased in a somewhat linear fashion as redemption rates increased.
Chaparro hopes that local WIC agencies will build on these findings and seek new ways to engage families at risk of dropping off. All WIC providers must offer nutrition education, which could be an opportunity to target households with lower redemption rates in popular categories.
The findings come just over a year after the U.S. Department of Agriculture, which oversees WIC, implemented significant updates to the program’s food package. Among other changes, the 2024 rule significantly increased benefits for fresh fruits and vegetables, which has proven popular.
“The expansion of fruit and vegetable benefits for WIC families has been among the most important policy changes of the last decade,” said Shannon Whaley, director of research and evaluation at PHFE WIC and co-author of the study. “Families want more fruits and vegetables, and this research demonstrates that their inclusion in the WIC food package is essential for longer-term engagement in the program.”
Non-uniform distribution of charges on the surface of iron oxides attracts diverse types of organic compounds through mechanisms with different binding energies.
While scientists have long known that iron oxide minerals help lock away enormous amounts of carbon — sequestering it from the atmosphere — a new Northwestern University study now reveals exactly why these minerals are such powerful carbon traps.
By exploring ferrihydrite, a common iron oxide mineral, engineers discovered it employs multiple, fundamentally different chemical strategies to grab carbon and lock it away.
Although ferrihydrite has an overall positive electrical charge, the engineers found its surface is not uniformly charged. Instead, its surface resembles a nanoscale mosaic of positively and negatively charged patches. And ferrihydrite does not trap carbon using electrostatic attraction alone. It also uses chemical bonds and hydrogen bonding to form strong chemical links between its surface and organic materials.
These unexpected strategies turn iron oxide minerals into highly versatile carbon snatchers, capable of grabbing and holding onto many different types of organic molecules. The findings offer new insight into how these minerals in soils trap carbon for decades or even centuries, preventing it from entering the atmosphere as climate-warming greenhouse gases.
The study was published today (Dec. 15) in the journal Environmental Science & Technology. The research provides the most detailed look yet at the surface chemistry of ferrihydrite, an important type of iron oxide minerals.
“Iron oxide minerals are important for controlling the long-term preservation of organic carbon in soils and marine sediments,” said Northwestern’s Ludmilla Aristilde, who led the study. “The fate of organic carbon in the environment is tightly linked to the global carbon cycle, including the transformation of organic matter to greenhouse gases. Therefore, it’s important to understand how minerals trap organic matter, but the quantitative evaluation of how iron oxides trap different types of organic matter through different binding mechanisms has been missing.”
Holding approximately 2,500 billion tons of sequestered carbon, soil is one of Earth’s largest carbon sinks — second only to the ocean. But even though soil is all around us, scientists are only just beginning to understand how it locks in carbon to remove it from the active carbon cycle.
In the new study, Aristilde’s group turned its focus to iron oxide minerals, which are associated with more than one-third of the organic carbon stored in soils. Specifically, the team examined ferrihydrite, a type of iron oxide mineral commonly found in soils near plant roots or in soils and sediments with abundant organic matter. Although ferrihydrite appears to be positively charged under many environmental conditions, it manages to bind a wide variety of organic compounds — some negatively charged, some positively charged and some neutral.
Watching molecules stick
To understand how this occurs, Aristilde and her team first used high-resolution molecular modeling and atomic force microscopy to gain a detailed look at the mineral’s surface. While the mineral’s charge is positive overall, the researchers found its surface actually contains intermixed patches of positive and negative charges. The finding explains why ferrihydrite can attract negatively charged species like phosphate and positively charged species like metal ions.
“It is well documented that the overall charge of ferrihydrite is positive in relevant environmental conditions,” Aristilde said. “That has led to assumptions that only negatively charged compounds will bind to these minerals, but we know the minerals can bind compounds with both negative and positive charges. Our work illustrates that it is the sum of both negative and positive charges distributed across the surface that gives the mineral its overall positive charge.”
After mapping ferrihydrite’s surface charges, Aristilde and her team tested how molecules bind to it, allowing them to connect surface chemistry directly to carbon trapping. They introduced ferrihydrite to organic molecules commonly found in soils, including amino acids, plant acids, sugars and ribonucleotides. Then, they measured how much of these molecules stuck to the ferrihydrite and used infrared spectroscopy to examine exactly how each molecule attached.
More than attraction
Ultimately, the team found that compounds bind to ferrihydrite using multiple strategies. While positively charged amino acids bonded to negative patches on ferrihydrite’s surface, negatively charged amino acids bonded to the positively charged patches. Other compounds, like ribonucleotides, are first drawn to ferrihydrite by electrostatic attraction and then go on to form much stronger chemical bonds with iron atoms. And sugars, which form the weakest bonds, are attached to the mineral through hydrogen bonding.
“Collectively, our findings provide a rationale, on a quantitative basis, for building a framework for the mechanisms that drive mineral-organic associations involving iron oxides in the long-term preservation of organic matter,” Aristilde said. “These associations may help explain why some organic molecules remain protected in soils while others are more vulnerable to being broken down and respired by microbes.”
Next, the team plans to investigate what happens after organic molecules are attached to mineral surfaces. Some compounds may undergo chemical transformations to products that are available for further degradation or to even more stable products that could be resistant to decomposition.
The study, “Surface charge heterogeneity and mechanisms of organic binding modes on an iron oxyhydroxide,” was supported by the U.S. Department of Energy and the International Institute for Nanotechnology.
BALTIMORE, Dec. 15, 2025 – New research published in the INFORMS journal Marketing Science finds that while Zillow’s widely used “Zestimate” home-valuation algorithm boosts efficiency in the residential real estate sector, it also significantly benefits lower-income neighborhoods even in situations where the algorithms are sometimes less accurate in those areas.
The study, “Unequal Impact of Zestimate on the Housing Market,” is authored by Runshan Fu of New York University; Yan Huang of Carnegie Mellon University; Nitin Mehta of the University of Toronto; Param Vir Singh of Carnegie Mellon University; and Kannan Srinivasan of Carnegie Mellon University.
The researchers used detailed Zillow and home-sales data from 4,027 properties across 140 neighborhoods in Pittsburgh, where the researchers built a structural model of the housing market. They sought to measure how Zestimate affects listing decisions, selling prices, time on market, buyer surplus and seller profit.
In the end, they found that because the Zestimate reduces uncertainty surrounding actual property values, it enables sellers to reduce the likelihood of selling their properties below market value. It also helps buyers to match with the homes they truly value, leading to purchases that better fit their specific needs and preferences. This has the effect of increasing the extra value, or buyer surplus, by 5.94%, and seller profit by 4.36% on average.
“Even when Zestimates under- or over-value a home, they reduce uncertainty about the property’s true market value and help clarify expectations for both the list price and the final offer,” said Yan. “Buyers and sellers make better-matched decisions, and the market as a whole becomes more efficient.”
The researchers found that the Zestimate algorithm tends to be less accurate in lower-income neighborhoods, but surprisingly, they benefit the most from its existence. This is due to the fact that those neighborhoods face higher baseline uncertainty about property values, so the Zestimate helps alleviate that uncertainty even with room for error.
The researchers found that seller profits increase by 4.78% in poorer neighborhoods, compared to 4.21% in wealthier neighborhoods. They found that the buyer surplus tends to increase by 9.09% in low-income neighborhoods, compared to 7.26 percent in wealthy neighborhoods.
“These results surprised even us,” said Nitin. “Zestimates actually narrow information gaps and reduce inequality by helping the buyers and sellers start the process with better information, more clarity and more reasonable expectations of what they can achieve.”
Param added, “If Zestimate accuracy in poorer neighborhoods were improved to the level of richer neighborhoods, the total economic surplus could increase by another 31%. That’s a substantial opportunity for improving fairness and efficiency in residential real estate.”
On the matter of accuracy, the study showed that 73% of properties with overvalued Zestimates still generated higher buyer surplus; and 44% of properties with undervalued Zestimates still produced higher seller profits.
“These algorithms create a win-win environment for both seller and buyer, and they don’t need to be perfect to create real value,” said Kannan. “Markets respond strongly to any signal that reduces uncertainty, and Zestimates do exactly that.”
Marketing Science is a premier peer-reviewed scholarly marketing journal focused on research using quantitative approaches to study all aspects of the interface between consumers and firms. It is published by INFORMS, the world’s largest association for professionals and students in operations research, AI, analytics, data science and related disciplines.
INFORMS serves as a global authority in advancing cutting-edge practices and fostering an interdisciplinary community of innovation. With a network of more than 12,000 members across academia, industry and government, INFORMS connects thought leaders and emerging professionals who apply science and technology to solve complex challenges and drive better decision-making.
Through its prestigious journals, world-class conferences, certification programs and professional resources, INFORMS empowers its community to enhance operational efficiency, elevate organizational performance and promote smarter decisions for a better world.
