What is the Nature of Part-Time Work in the United States and Japan?

TLDR: Part-time employment represents a large and growing share of employment in most industrialised countries as mentioned in this paper, and many workers seek part-time positions to accommodate child care and household responsibilities, school, or other activities.

Abstract: Part-time employment represents a large and growing share of employment in most industrialised countries. One view holds that the amount of part-time employment simply reflects the efficient outcome of supply and demand forces in the labour market. Some workers seek part-time positions to accommodate child care and household responsibilities, school, or other activities. Firms demand part-time workers to increase staffing during peak business hours or to solve other scheduling problems. The relative wages of part-time workers adjust until the supply of part-time workers equals the demand for part-time workers. Another view treats labour markets as segmented, with part-time jobs falling in the secondary sector. Detractors of part-time employment argue that these jobs typically pay low wages, offer few fringe benefits, and have little job security. Moreover, labour markets may not clear in the neo-classical economic sense and many workers desiring regular, full-time jobs work part-time involuntarily.