of audit quality, ISPEC, and ACCY is positive and significant at p 0.01. The correlations
among control variables are generally low, except the correlations between AUDITOR and
SIZE, EL and LOSS, STDROE and SURPRISE, and INVMR and LOSS. The strong relationship
between AUDITOR and SIZE is reasonable because large companies are more
likely to hire Big 5 auditors. The relationship between STDROE and SURPRISE is also
understandable because the stable companies are less likely to report greater surprise. Because
earnings per share are used to derive the LOSS variable, the EL and LOSS variables
are highly correlated. As reported in the bottom row of Table 2, the inverse Mills ratio
(INVMR) is highly correlated with several firm characteristics.