Search Results
Journal Article
The Determinants of Mortgage Denial
We analyze over 30 million home purchase mortgage applications from 2018–2024 using publicly available Home Mortgage Disclosure Act (HMDA) data to study the determinants of mortgage denial. We establish three primary findings. First, credit access is highly sensitive to monetary policy; the 2022–2023 tightening drove aggregate denial rates from 12.2% to 15.7% via the debt-to-income (DTI) channel. Second, we identify a critical nonlinearity in underwriting: While the 43% qualified mortgage (QM) threshold—below which lenders receive legal safe harbor from ability-to-repay claims—is ...
Working Paper
Algorithms as Shadow Regulation: Secondary Market Access Overrides Home Buyer Credit Risk
Using confidential HMDA data on 30 million purchase applications, we show how automated underwriting distorts credit allocation. We document a severe 7.5-percentage point jump in denials at the 50% debt-to-income threshold. This "cliff" is unique to Fannie Mae’s software, whereas Freddie Mac’s algorithm exhibits no matching friction. By exploiting institutional routing to isolate secondary market access as the causal mechanism, we find a stark price-quantity asymmetry: the interest rate penalty is a mere 3 basis points, yet the threshold suppresses $7.7 billion in conventional ...
Failing the Threshold: The Impact of Rising Interest Rates on Mortgage Borrowing
Denials moved closely with rising U.S. mortgage rates in 2022 and 2023, showing higher borrowing costs—not weaker applicants—drove the increased rejections.
Working Paper
The Interactions of Social Norms about Climate Change: Science, Institutions and Economics
We study the evolution of interest in climate change among different actors within the population and how the interest of these actors affects one another. First, we document the evolution of interest for each actor individually, and then we provide a model of cross-influences between them. We estimate this model using a Vector Autoregression (VAR). We measure interest among the general public, the European Parliament, central banks, general interest science journals, and economics journals by creating a Climate Change Index (CCI) based on mentions of climate change in these domains. Except ...
When Houses Outrun Paychecks: The Lost Decades of Housing Affordability
An analysis of housing and household income data from 2000 to 2023 finds that in most U.S. counties, the cost of buying a house has outpaced local incomes.
Working Paper
The Determinants of Mortgage Denial Using Public Data
We analyze over 30 million home purchase mortgage applications from 2018-2024 using publicly available Home Mortgage Disclosure Act (HMDA) data to study the determinants of mortgage denial. We establish three primary findings. First, credit access is highly sensitive to monetary policy; the 2022-2023 tightening drove aggregate denial rates from 12.2% to 15.7% via the debt-to-income (DTI) channel. Second, we identify a critical nonlinearity in underwriting: While the 43% qualified mortgage (QM) threshold---below which lenders receive legal safe harbor from ability-to-repay claims---is ...
Working Paper
Prior Knowledge, Module Design, and Student Dropout in Online K-12 Education
We examine student dropout in online K-12 education coursework using administrative data for 442,000 students, 64 economics and personal finance modules, and 2.1 million module assignments between 2014 and 2025. We find that module length, prior knowledge, embedded formative assessments, and school district demographics independently predict whether students complete assigned modules. Each additional page is associated with a 0.24-percentage-point decrease in completion probability, but this relationship is 30 percent weaker for students with above-median prior knowledge. Embedded knowledge ...
America Underbuilt Inc.: The Supply Side of the U.S. Housing Challenge
This analysis finds that the U.S. has underbuilt housing for decades. The persistent supply shortfall amid growing demand drives today’s affordability crisis.
What 30 Million Applications Reveal about Mortgage Denial Thresholds
A debt-to-income ratio of 43% was long considered to be a threshold for mortgage applicants. This analysis finds the true threshold is 50%.
The Mortgage Borrower Who Can’t Fail and the One Who Can’t Win
Why do first-time buyers face higher mortgage denial rates than those buying a second house? This analysis examines the structural market forces that shape access to credit.