Job sector or PSM? Examining the relative effects of sector and public service motivation on prosocial behaviour

Since public service motivation (PSM) arose from the literature on public/private differences and explaining what motivates workers in government, job sector and PSM intertwine. Many have examined how PSM relates to job sector and have even used job sector as a proxy for PSM, but are job sector and PSM interchangeable? More specifically, does sector or PSM drive individuals to prosocial behaviour? We use volunteering to decompose the relative contribution of employment sector and PSM to engaging in prosocial behaviours. We find nearly the entire cross-sector gap in prosocial behaviours is driven by differing average levels of PSM and observables.