In the mainstream real business cycle (RBC) model, labor can be viewed as temporary employment since the firm's demand for labor behaves directly in response to stochastic productivity shocks in each period. This paper provides a tractable way of analyzing fluctuations in permanent and temporary employment over the business cycle, as well as the underlying driving forces. This inclusion of heterogeneity helps reconcile the RBC model with the U.S. data given that temporary employees in general only account for a small proportion of total private‐sector employment (about 2%–3%). We draw an explicit division between permanent and temporary employment and resort to this separation to account for stylized facts that characterize a two‐tier labor market. In particular, with regard to the U.S. labor market, our benchmark model can well explain the motivating facts: (1) temporary employment is much more volatile than permanent employment, (2) the share of temporary employment (the ratio of temporary to aggregate employment) exhibits strong pro‐cyclicality, (3) permanent employment lags by two quarters on average, and (4) the correlation between temporary employment and output is stronger than that involving the permanent counterpart. The quantitative analysis suggests that our proposed channels explain the main facts well and the model further provides plausible reasoning for a firm's labor hoarding.