This dissertation includes three papers that examine part-time work and work hour preferences. The involuntary part-time employment rate is defined as the share of employed workers who work part-time but would prefer to work full-time. The first paper investigates the determinants of the involuntary part-time employment rate by accounting for both labor supply and labor demand, while the second paper compares the patterns and determinants of involuntary part-time employment during the Great Recession and the COVID-19 recession. The third paper shifts attention to a particular industry with a high prevalence of part-time workers, the food retail sector, and examines workers’ experience during the early stages of the COVID-19 pandemic. Paper 1, titled “The Labor Demand Side of Involuntary Part-time Employment,” investigates the determinants of the involuntary part-time employment rate (i.e., the proportion of involuntary part-time workers in all employment) by accounting for both labor supply (unemployment) and labor demand (job vacancies). We use big data on the near universe of online job vacancies collected by Burning Glass Technologies and the Current Population Survey from 2003 to 2021. We find that, within a commuting zone by 6-digit SOC occupation cell, a 10% increase in the unemployment rate increases the involuntary part-time rate by 0.19 percentage points, while a 10% increase in job vacancies decreases the involuntary part-time rate by 0.07 percentage points. We also provide suggestive evidence that higher labor market concentration, which is indicative of greater employer power in the labor market, may raise involuntary part-time employment. Overall, we conclude that higher labor supply and lower labor demand increase involuntary part-time employment. How did the COVID-19 recession affect part-time workers who wanted full-time jobs? The second paper, titled "Involuntary Part-time Employment in Two Recent Economic Downturns: Lessons from the Great Recession and the COVID-19 Recession," compares the impact of the Great Recession and the COVID-19 recession on involuntary part-time employment. Using data from the Current Population Survey from January 1994 to December 2022, we examine the patterns and determinants of involuntary part-time work. Based on the experience of the Great Recession, one would have expected a large increase in involuntary part-time work during the COVID-19 Recession, when unemployment surged to more than 15%. Relative to these expectations, the growth of involuntary part-time employment in 2020 was subdued. This can be explained by unique factors, such as workers transitioning to unemployment due to business closures and changes in consumer behavior. Contact-based industries, like leisure and hospitality, experienced higher unemployment rates and lower shares of involuntary part-time workers. In the most adversely affected industries, employers were not able to adjust with hours reduction – which would have increased involuntary part-time work – but instead resorted to laying off workers. The labor market recovery in 2020 was remarkably swifter than the recovery after 2009, with substantial decreases in both involuntary part-time employment and unemployment within a few months. This paper highlights how the COVID-19 recession reshape the labor market through unemployment rather than underemployment, and how favorable conditions facilitate a surprisingly rapid recovery. Lastly, paper 3, entitled “Work Attendance Anxiety, Precarious Work Schedules, and Job Satisfaction of Essential Retail Workers during early COVID-19”, turns attention to food retail part-time workers. Building upon the Job Demands-Resources model (JD-R), the study examines the relationships among precarious work schedules, work attendance anxiety: anxiety over going to work, and employer supports during the early pandemic among essential retail workers who were required to continue working on-site. Data were collected through an online survey on the Amazon Mechanical Turk platform. Between July and August 2020, we secured a sample of U.S. part-time workers in “food and beverage retail stores” (N=179). Using Ordinary Least Squares (OLS) regression analyses, the findings indicate that attendance anxiety, lack of control over work hours, and non-standard working hours are negatively associated with job satisfaction. In terms of employer support, personal protective equipment reduce the level of attendance anxiety and alleviate the impact of attendance anxiety on job satisfaction. The findings from this study provide insights for employers and managers to improve the job satisfaction of essential workers in the food retail sector.