“…5 Given a measure of income separate from that reported to shareholders, booktax differences, and its components, have been used to address a number of accounting issues, such as the quality of accruals (Joos et al 2002), tax shelters (Plesko, 2000b;Manzon and Plesko, 2002;Desai, 2003) the persistence of financial accounting earnings, (Hanlon, 2003a), earnings management (Phillips et al, 2003), and accounting conservatism (Watts, 2003).…”