Working more for less : part-time penalties across the working hours distribution?

We use German administrative and survey data to investigate the heterogeneity of parttime penalties in hourly wages and growth rates. Exploiting tax reforms for identification, we find substantial heterogeneity in part-time wage penalties from −28.3% to −7.2% compared to full-time. The heterogeneity in wage growth penalties is less pronounced. Both penalties do not decrease linearly with additional working hours. More weekly working hours might result in a higher hourly wage penalty. The shape of the penalties is driven by workers with non-demanding tasks and professions where working around 30 weekly hours is uncommon, and relatively many females work.