Yu Wu
After the financial crisis, policy rates in the major advanced economies have moved downwards to near/below zero. Some countries have experienced an increase in house prices and an expansion of mortgages. Also, there have been considerable changes in the mortgage market share, with only a few bank categories contributing to this mortgage expansion. Such change in exposure to real estate risk may pose a risk to financial stability. My dissertation research studies the role played by specific bank features, such as reliance on deposits and covered bonds or capital surplus relative to the required level, in explaining banks' different mortgage lending behavior. The first chapter (joint with Prof. Luisa Lambertini) studies the Swiss mortgage market dynamics in a low rate environment. After 2008, small banks (cantonal banks and Raiffeisen) have primarily contributed to this mortgage expansion at the expense of two big global systemic banks (UBS and Credit Suisse). We set up a model featuring big and small banks that compete in the deposit and mortgage market and face different capital requirements. We calibrate it to the Swiss banking sector. In this model, a falling policy rate drives up borrowing demand and leads to an expansion in mortgage supply; however, an asymmetric tightening of capital requirement gives small banks a competitive advantage and causes a shift in market share towards small banks. In the second chapter, with Prof. Luisa Lambertini, we use the Swedish bank-level data and employ a triple diff strategy to investigate whether funding side differences also play a role in explaining banks' different lending responses to the negative rate policy. First, we find that high-deposit banks expand their mortgage supply less than low-deposit banks during negative rate periods, confirming the well-documented deposit channel effect. However, this pattern works only for weakly-capitalized banks, which have a low capital buffer. Second, we show that banks more reliant on covered bonds to finance mortgage lending lend out more under negative rates; they can shift into cheap deposits to reduce their funding costs. We extend our model in the first chapter to be consistent with these empirical findings and use it to study the implications of the Covid-19 pandemic for the mortgage market. The third chapter analyzes the transmission of housing price dynamics to the real economy in the context of China, which went through a decade-long housing boom. Understanding its propagation to other economic activities is thus important. I build up a real business cycle model for this study and find that land-use conversion by the governments and land finance of housing firms can amplify the crowding-out effects of housing price fluctuations on the non-housing sector. The year 2020 was marked by the outbreak of the Covid-19 pandemic, which adversely affected the labor market. The fourth chapter is an additional line of work, with Dr. Corinne Dubois and Prof. Luisa Lambertini exploring gendered consequences of the pandemic in the Swiss labor market. We use the Swiss labor force survey data and find that all else equal, women have been more likely to exit the labor market altogether or to use short-term working schemes than their male counterparts. Contrary to expectations, increased family-care responsibility is not the main driver. Telework availability of occupation, however, explains some of the differential impact of Covid-19 on men and women.
EPFL2021
