Commitment, advertising and efficiency of two-sided investment in competitive search equilibrium

Competitive search entails both commitment to and advertising of pay-off relevant aspects of market participants. This paper considers incrementally the implications of each in a labor market where both workers and firms invest prior to market entry. A wide range of institutional arrangements are addressed within the same general framework. When the characteristics of jobs or workers are advertised the efficient outcome pertains. Commitment without advertising typically leads to market unravelling: the Diamond paradox. But, whenever wages and human capital are advertised, firms become residual claimants; the private and social returns to investment coincide. Absent wage commitment, the Hosios condition implies efficiency when investments are advertised.