Profitability Ratio Analysis for Professional Service Firms

Abstract

The DuPont analysis is one of the most commonly used financial analysis tools for traditional businesses. It disaggregates return on equity (ROE) into profit margin (PM), asset turnover (ATO), and leverage (LEV) thereby providing value-relevant information relative to aggregated profitability. In this paper, I extend the use of the DuPont model to the professional service industry. The professional service industry has recently become one of the fastest growing segments driving the U.S. economy (USITC 2009, U.S. Census Bureau of Economic Analysis 2009). Unlike traditional businesses whose key business assets are their physical assets, professional service firms rely on human capital assets that are not recognized in the balance sheet. I introduce a profitability ratio analysis model that focuses on human capital. I validate the model by examining whether the disaggregated profitability ratios for professional service firms add relevant information over aggregated ratio in the same way as they do for traditional businesses. I use law firms as a representative segment of the professional service sector to empirically evaluate my model. I collect financial and human resource data for 81 of the 100 largest U.S. law firms from 2000 to 2007 then disaggregate profit per equity partner (PPP) into the three profitability ratios: profit margin (PM), revenue per lawyer (RPL), and leverage (LEV). I compare the absolute forecasting error (AFE) of the simple AR (1) model that uses only the current year profit per equity partner (PPP) to forecast one-year ahead profit per equity partner (PPP) and my model that uses the three profitability ratio model (PM, RPL, and LEV) of current year to forecast one-year ahead profit per equity partner (PPP). I find that using the disaggregated profitability ratios significantly improves forecasting of future profitability relative to using only profit per equity partner (PPP), analogous to similar results documented for the DuPont model in Fairfield and Yohn (2001) and Soliman (2004). I examine which firm characteristics are associated with the profitability ratios. I include four firm characteristics variables (STRUCTURE, SCOPE-INTL, SCOPE-RGNL, and SCALE) that are commonly used in economic analysis of industrial organizations. I find that the profitability ratios are systematically associated with firm characteristics that reveal information on the business models of individual firms. Leverage (LEV) is higher in law firms with non-equity partners (STRUCTURE), international focus (SCOPE-INTL), regional focus (SCOPE-RGNL), or large size (SCALE). Law firms that are large sized (SCALE) or regional focused (SCOPE-RGNL) command premium fee (high RPL) on average, but law firms with international focus or with non-equity partners do not.