Julie Marx
Associate Professor
Primary research areas
Household Finance
The Housing Market
Behavioral Economics
Studying Household Behavior in Denmark
I am an Associate Professor at Copenhagen Business School (CBS), specializing in household finance. My research focuses on how families make financial decisions, with a special interest in the housing market and mortgages. I study how people buy, sell, and finance homes — and how these choices are shaped by financial constraints, incentives, and behavioral patterns.
I often draw on insights from behavioral economics to explore how psychological factors influence financial decisions. I am also interested in gender economics, including how gender roles and dynamics affect economic outcomes in households.
Recently, I have developed an interest in how households respond to changes in electricity prices, with a focus on understanding behavioral reactions to energy costs.
My research has been published in leading academic journals and aims to contribute to a better understanding of how real people make economic decisions in everyday life.
Recent research projects
From Rates to Riches: How Danish Homeowners Respond to Interest Rate Shocks
This paper investigates the real effects of a large, positive net-worth shock experienced by Danish fixed-rate mortgage (``FRM'') borrowers in 2022, when rising long-term interest rates enabled them to repurchase their mortgages at steep discounts.
Unlike U.S. FRMs, Danish mortgages allow borrowers to monetize capital gains when rates rise, creating a unique setting to study household responses to large wealth shocks.
Using high-quality microdata, we document that many households refinanced to capture gains, reducing debt or increasing consumption and investments.
A structural model confirms heterogeneous responses across mortgage types, highlighting the role of institutional design in shaping monetary policy transmission.
Watt Changes: Households' Response to Hourly Electricity Prices
A successful green transition requires aligning electricity demand with renewable supply, which variable pricing can achieve. We use novel high-frequency data on electricity consumption and an instrumental variable approach to analyze electricity price responsiveness of Danish households. We estimate electricity price elasticities across and within days. We find that higher prices lead households to adjust their consumption, mostly through level decreases rather than shifting use to cheaper off-peak hours. The level cuts persist after prices fall, especially for lower-income households, while within-day shifting is modest and concentrated among higher-income households.