“…This allows us asking and answering the questions whether nonprofit organisations employ lower productivity workers and pay them less than other types of organisations within the sector. In fact, previous contributions have already studied the determinants of the nonprofit wage gap (see, for instance, Preston, 1989;Leete, 2000;Ruhm and Borkoski, 2000;Pestana Barros, 2006;Mosca, Musella and Pastore, 2007), though leaving aside the issue of the possible differences in returns to human capital across organisations' types. This paper finds clear evidence that the 1 In fact, the use of informal contacts, such us the help of family and friends or other forms of recommendations, is a common search and recruitment strategy in the U.S., as Corcoran, Datcher and Duncan (1980), Holzer (1988) and Ioannides and Datcher Loury (2004), among others, note, but also in the UK (Gregg and Wadsworth, 1992), in the European Union (Pellizzari, 2004) and in Italy (Pistaferri, 1999;Meliciani and Radicchia, 2005).…”