Several portfolios sorted by size, labor cost disclosure status, and human capital indicators
are formed annually and their performance measured using the risk-adjusted measures for portfolio (or fund) performance evaluation, namely Jensen’s and Treynor’s indices. Our study extends prior related literature in accounting and financial economics in two ways; we examine the market valuation and performance effects of labor cost voluntary disclosures using a portfolio performance approach while related voluntary disclosure valuation studies have focused on accounting valuation models