SIQI WEI
Welcome to my website!
I received my PhD in Economics at CEMFI. My research focuses on applied econometrics, with a special interest in understanding individuals' income and health dynamics, and their interactions with other labor market outcomes, such as employment decisions.
Methodologically, I am interested in latent-variable models and their estimation.
References
Manuel Arellano (Main advisor) arellano@cemfi.es
Dmitry Arkhangelsky darkhangel@cemfi.es
Pedro Mira mira@cemfi.es
Josep Pijoan-Mas pijoan@cemfi.es
WORKING PAPERS
Presentation: EWMES 2021, AMES China 2022, EEA-ESEM 2022, UNIA workshop, Bank of Spain, SAEe 2022, SOLE 2023, IAAE 2023
This paper begins with the observation that many older workers move to "bridge" jobs with lower wages and fewer working hours before exiting the labor force for good. To explain this smooth transition to full retirement, I propose a nonlinear aging-related shock — mismatch shock, which mismatches workers with their existing job and triggers job leaves. I develop an empirical framework of employment and job transitions jointly with stochastic wage and hour processes, which allows us to separate health risks, individual-specific productivity risks, firm-specific mismatch risks, quality of outside offers, and job destruction risks faced by older workers. The model is estimated with a sample of male individuals aged 51 to 70 in the US Health and Retirement Study applying a novel parameter-expanded stochastic EM algorithm. The paper finds that mismatch shocks play an important role in explaining the reduction in wages and hours for movers. Shutting down mismatch shocks implies that the mean wage drop of movers is reduced by around 55%, and the variance of wage changes is reduced by 17% − 28%, depending on age groups. Furthermore, I calculate the welfare cost of risks and quantify how much individuals value the possibility of a flexible transition to full retirement by constructing a utility-based structural model of consumption, employment and job movements where agents face the same risks as in the empirical model. The model is estimated using a novel simulation-based algorithm that exploits the connection to the empirical model and the estimates from the empirical model. The results show that the median cost of mismatch risks amounts to a reduction in consumption flow by 5.3%−7.1% depending on the education group. Banning job changes and re-entry causes a welfare loss equivalent to a consumption drop of 12% − 14%.
PUBLICATIONS
This paper presents new estimation algorithms for three types of dynamic panel data models with latent variables: factor models, discrete choice models, and persistent-transitory quantile processes. The new methods combine the parameter expansion (PX) ideas in Liu et al. (1998) with the stochastic expectation-maximization (SEM) algorithm in likelihood and moment-based contexts. The goal is to facilitate convergence in models with a large space of latent variables by improving algorithmic efficiency. This is achieved by specifying expanded models within the M step. Effectively, we are proposing new estimators for the pseudo-data within iterations that take into account the fact that the model of interest is misspecified for draws based on parameter values far from the truth. We establish the asymptotic equivalence of the likelihood-based PX-SEM to an alternative SEM algorithm with a smaller expected fraction of missing information compared to the standard SEM based on the original model, implying a faster global convergence rate. Finally, in simulations we show that the new algorithms significantly improve the convergence speed relative to standard SEM algorithms, sometimes dramatically so, by reducing the total computing time from hours to a few minutes.
Income Risk Inequality: Evidence From Spanish Administrative Records (with Manuel Arellano, Stéphane Bonhomme, Micole De Vera, and Laura Hospido), Quantitative Economics, (13)4: 1747-1801, 2022 paper
In this paper we use administrative data from the social security to study income dynamics and income risk inequality in Spain between 2005 and 2018. We construct individual measures of income risk as functions of past employment history, income, and demographics. Focusing on males, we document that income risk is highly unequal in Spain: more than half of the economy has close to perfect predictability of their income, while some face considerable uncertainty. Income risk is inversely related to income and age, and income risk inequality increases markedly in the recession. These findings are robust to a variety of specifications, including using neural networks for prediction and allowing for individual unobserved heterogeneity.
WORK IN PROGRESS
More than 30% of spouses retire within a year of each other in Europe, despite their age difference. This suggests the existence of complementarities in spouses’ retirement decisions. At the same time, almost 60% of Europeans retire before official retirement age, usually with a penalty in pension wealth. In this paper, I study complementarities in retirement decisions among European couples when earlier retirement options are available. Using data from SHARE I estimate an interdependent duration model allowing for early and joint retirement with positive probability. Empirically I find that early retirement and joint retirement are economically im- portant for European couples. Importantly, ignoring the early retirement penalty in pensions’ wealth leads to an underestimation of the complementarities in spouses’ retirement decisions. Results suggest that being retired at the same time increases each spouse’s indirect utility by approximately 13%. When early retirement –and its associated penalty– is not accounted for in the model, results show that complementarities increase each spouse’s utility only by 9% . To gauge the importance of complementarities in retirement decisions, I conduct a counterfactual exercise by increasing the husband’s full retirement official age by 60 months. I find that such a policy leads to a reduction of 5% in the husband’s hazard and almost 3.5% in that of his wife. These findings suggest that, by ignoring joint and early retirement, governments may be misestimating the impact that a policy on retirement decisions might have.
DISCUSSIONS
"On the Asymmetrical Sensitivity of the Distribution of Real Wages to Business Cycle Fluctuations" by Rodrigo Barrela, Eduardo Costa, and Pedro Portugal, 2nd BdE and BdP Conference on Labour Markets, 2024, Madrid slides
TEACHING
Econometrics, undergraduate level, spring semester 2023, 2024
Microeconometrics, master's level, spring 2023, 2024
Introductory Statistics: Teaching Assistant for Prof. Laura Hospido, graduate level, summer 2019
Econometrics: Teaching Assistant for Prof. Ivan Fernandez-Val, graduate level, winter 2019
Econometrics: Teaching Assistant for Prof. Manuel Arellano, graduate level, winter 2018
Panel Data Econometrics: Teaching Assistant for Prof. Manuel Arellano, summer school course, summer 2017