SIZE has no significant impact on IO for both the OLS (t = –0.633) and 2SLS
(t = –0.890) results. Consistent with the research of O’Brien and Bhushan (1990), and
Crutchley et al. (1999), ROA was found to be a significant determinant of INST for either
the OLS or 2SLS results, possibly due to the similar rationale for the
non-significance of proxy Q in Equation (2). DEBT has a significant and negative impact
on IO in the 2SLS (t = –1.873) results at 10% significance level, but not in the OLS
results. Since 2SLS is consistent in estimating Equation (2), DEBT is determined to be
a significant determinant of IO. Thus, higher debt ratios lead to lower IO percentages. This
finding is consistent with the notion that higher debt ratios diminish the need for
institutional monitoring and result in lower shareholdings by institutions (Demsetz and
Villalonga, 2001; and Welch, 2003). It also indicates that debt and IO may have become
substitutes for each other in the agency framework. In other words, low leverage in our
sample may give more room for institutions to play their monitoring role, thus creating
an incentive for them to hold more shares.