7. Personal Financial Advice and Portfolio Quality with Olga Balakina, Tobin Hanspal, Andreas Hackethal and Dominique Lammer (November 2025)
Available as a SAFE working paper
Media mentions our work: The FinReg Blog, FAZ
Conditionally accepted at the Review of Finance (and resubmitted)
Abstract: We document widespread use of personal financial advice among retail investors. Individuals seek competent and trusted sources for financial advice among their family and friends. Investors who provide advice to family and friends are positively selected and emphasize the reputational costs of giving risky financial advice. While previous studies have shown that advice shared on social media promotes active trading, we show that personal financial advice encourages investing in funds over single stocks. Our evidence complements the existing literature on financial advice in online social networks by highlighting differences in incentives and outcomes of advice to close personal connections.
6. Beyond Connectivity: Stock Market Participation in a Network with Olga Balakina and Anastasiia Parakhoniak (October 2025)
Available as a SAFE working paper
Accepted subject to minor revisions at the Journal of Economic Dynamics and Control (and resubmitted)
Abstract: What are the aggregate and distributional consequences of the relationship between an individual’s social network and financial decisions? Motivated by several well-documented facts about the influence of social connections on financial decisions, we build and calibrate a model of stock market participation with a social network that emphasizes the interplay between connectivity and network structure. Since connections to informed agents influence peers through utility and learning, there is a pivotal role for homophily. An increase in the average number of connections raises the average participation rate, mostly due to richer agents. Higher homophily benefits richer agents by creating clusters where information spreads more efficiently. We also show that social utility is crucial for matching stock market participation among poorer agents. Finally, we provide empirical evidence consistent with the importance of connectivity and sorting.
5. Mortgage Design, Repayment Schedules, and Household Borrowing with Peter van Santen and Patrick Moran (April 2025)
Available as FEDS WP 2024-077 and SAFE working paper No 421.
Blog post summarizing the paper
Accepted at the Review of Financial Studies
Abstract: How does the design of debt repayment schedules affect household borrowing? To answer this question, we exploit a Swedish policy reform that eliminated interest-only mortgages for loan-to-value ratios above 50%. We document substantial bunching at the threshold, leading to 5% lower borrowing. Wealthy borrowers drive the results, challenging credit constraints as the primary explanation. We develop a model to evaluate the mechanisms driving household behavior and find that much of the effect comes from households experiencing ongoing flow disutility to amortization payments. Our results indicate that mortgage contracts with low initial payments substantially increase household borrowing and lifetime interest costs.
4. Mortgage Innovations and House Price Booms with Chandler Lutz
Available as an ungated working paper
Journal of Urban Economics, Volume 145, January 2025
Abstract: We study how mortgage innovation can cause a housing boom even within a robust regulatory framework and strictly enforced recourse borrowing. Specifically, we find that the 2003 introduction of interest-only (IO) mortgages in Denmark ignited a housing boom that increased house prices 36 percent. In line with IO loans lowering debt-service payments and relaxing payment-to-income constraints, results show higher IO loan uptake and house price growth in areas with greater ex-ante benefits of such mortgages. Overall, our results are relevant for the many countries where IO loans play a sizable role in mortgage finance.
3. Interest-Only Mortgages and Consumption Growth: Evidence from a Mortgage Market Reform with Natalia Khorunzhina
Available as an ungated working paper
International Economic Review (2024), Volume 65, Issue2, May 2024
Abstract: We use household-level data to analyze how the introduction of interest-only (IO) mortgages in Denmark affected consumption expenditure and borrowing. Using an ex ante measure of exposure to the IO mortgage reform motivated by mortgage-payment and leverage constraints, we show households more likely to use an IO mortgage to relax their mortgage-payment constraint increased consumption following the reform. This increase in consumption is financed by borrowing at the time of refinancing and by borrowers with lower prereform leverage and higher needs for liquidity. We find even larger postreform consumption growth for the leverage-constrained homeowners through house-price growth stimulated by the reform.
2. Participation and Losses in Multi-Level Marketing: Evidence from an FTC Settlement with Tobin Hanspal
Available as an ungated working paper
Financial Planning Review (2022)
Abstract: More than 20 million Americans are affiliated with multi-level marketing firms (MLMs), but there is little empirical evidence on who participates in this controversial part of today's labor market. We link data on 350,000 individuals cited in an Federal Trade Commission settlement with one of the largest MLMs to detailed county-level information. We find that the share of refund claimants is greater in areas with higher median income and where women are absent from the labor market, suggesting value in flexible work. However, check amount, a proxy for losses, are correlated with higher inequality and lower social capital, suggesting that the pitfalls accrue to vulnerable groups.
1. The Impact of Interest-Only Loans on Affordability with Chandler Lutz
Available as an ungated working paper
Regional Science and Urban Economics (2020)
Abstract: We study the 2000s Danish legalization of interest-only (IO) loans, a mortgage market innovation aimed at increasing affordability and homeownership rates for cash-strapped buyers by substantially reducing first-year payments. Our results show that IO mortgages rapidly became popular in regions with higher house prices pre-treatment as well as with both the targeted cash-strapped borrowers and mortgage applicants spanning the wealth and income distributions. Just three years after policy implementation, IO mortgages constituted half of all outstanding Danish mortgages. The introduction of IO loans thus led to an increase in housing turnover and transactions. However, as these increases were dispersed across the distribution of homeowners, they did not lead to any changes in homeownership rates for the targeted group or allow any underserved buyer groups to enter the market. Broadly, our policy analysis documents how reforms targeting housing affordability and inequality can be exploited by the wider population, limiting intended effects.
1. Housing returns across the income distribution with Natalia Khorunzhina and Walter D'Lima (new draft coming soon)
Selected presentations: EEA 2025, UEA2025, 2025 CEAR-RSI Household Finance Workshop, ReCapNet 2025
Abstract: We show that high-income buyers earn higher financial returns to housing using detailed transaction data from Denmark. The gap in housing returns is explained by location, with little role for market timing, property type, buyer characteristics, or risk-taking. Higher-income households purchase in areas with persistently higher house price growth but comparable risk, liquidity, and downside exposure to those chosen by lower-income households.Credit constraints and consumption needs limit the feasible choice set of lower-income households, limiting access to high-return locations. Our results highlight how spatial sorting amplifies differences in wealth accumulation: returns on the largest household asset are shaped less by risk or investment skill than by consumption needs, housing supply, and financial constraints.
2. Macroprudential policies and homeownership rates: Cross-country evidence
A summary of the paper is available on Substack
Under review
Abstract: Macroprudential policies are a key policy tool for financial regulators, but concerns persist that these policies restrict access to homeownership. I examine this concern using cross-country data on homeownership for 28 countries. I find little evidence that macroprudential policies reduce homeownership rates in aggregate or for select groups such as low-income households. The estimates are precise enough to rule out large negative effects of macroprudential policies on homeownership rates. The null effects are consistent with models where credit shocks primarily affect prices rather than quantities. My results alleviate concerns that macroprudential policies systematically exclude certain households from ownership, but also indicate that relaxing such policies is unlikely to increase access to homeownership.
3. When Markets Get Confused: Misperception versus Inventory (with Arze Karam, Olga Balakina, and Anastasiia Parakhoniak)
Project supported by the British Academy/Leverhulme Grant SRG1819S
Abstract: We examine episodes in which investors mistakenly trade similarly named stocks to identify short-term, non-fundamental pricing errors. Using a long time series and a broad cross-section of U.S. equities, we systematically document the frequency, magnitude, and market response to these "confusion events". These incidents generate pronounced abnormal returns and wider effective spreads, consistent with transient mispricing. By exploiting confusion events as exogenous, we provide new causal evidence that such dislocations primarily arise from investor misperception rather than inventory frictions. Importantly, the two channels are not mutually exclusive but represent orthogonal sources of inefficiency—belief-driven demand shocks versus dealer balance-sheet constraints. We demonstrate that, under normal conditions, the misperception channel dominates, whereas under systemic stress, inventory constraints become binding. This duality bridges the behavioral and structural perspectives on market inefficiency, underscoring that belief errors remain a pervasive driver of transient dislocations, even in deep, liquid, and technologically advanced markets.
4. Mortgage market design and wealth inequality: Evidence from interest-only mortgages in Denmark with Danial Ali Akbari, Natalia Khorunzhina and Timo Trimborn
Selected presentations: Echoppe Conference on the Economics of Housing and Housing Policies, St Gallen workshop on Macroeconomic Implications of Housing, Household Finances, and Wealth Dynamics.
Abstract: Mortgage markets around the world are designed to help household build home equity through debt repayment, but may also restrict portfolio choice. We study the impact of mortgage repayment design across the wealth distribution in Denmark, where interest-only mortgage without mandatory amortization payments are popular both among rich and poor borrowers. We show that borrowers build up less wealth and consume more after refinancing to an interest-only mortgage. While the savings response to switching to an interest-only mortgage is similar for rich and poor, mortgage amortization is an ex-ante more important form of savings for low wealth households. Consequently, interest-only mortgages increase wealth inequality but decrease consumption inequality. Overall, our results highlight that mortgage market design affects savings and wealth inequality.
House Prices, Expected Tenure, and Consumption Growth
Financial Constraints and Homeownership (project funded by a Marie Skłodowska-Curie Fellowship)
Monthly Payment Targeting and Borrowing: Experimental Evidence
Experimental Evidence on Peer Effects in Finance: Mindful or Mindless Imitation?
Mortgage Borrowing, Renovations, and Housing Returns