Table 9.6 shows the respective ǻR^2 statistics for the four team outcomes, of both the vertical strategic
leadership dimensions and the shared strategic leadership dimensions. When controlling for the
impact of industry, the multiple regression analyses show that shared Business development (ȕ=.43,
p<.05) was a significant predictor for Market proactiveness, explaining 16% (above the variance
explained by industry). Equally the regression results showed that shared Client centricity was a
significant predictor for Market responsiveness (ȕ=.32, p<.10), explaining 11% of variance, pectively.
Shared leadership was no significant predictor for either Innovation of Efficiency. Vertical leadership
was no significant predictor for any of the four effectiveness scores considered in this study.
An important component of this research was determining the relative usefulness of vertical and
shared strategic leadership in predicting team effectiveness. To do so, hierarchical regression models
were specified, in which the order of entry for vertical and shared leadership was manipulated and
examined for each of the dependent variables (Efficiency, Innovation, Market proactiveness, Market
responsiveness). The appropriate test statistics for this comparison were the ǻR^2 statistics found in
Step 3, when comparing the upper and lower table (Table 9-7). In case the ǻR^2 in Step 3 was larger
for the upper table, shared leadership was a more significant predictor than vertical leadership. If the
ǻR^2 was larger in the lower table (for Step 3), than vertical leadership was a more important predictor
(than shared leadership) for that the respective team outcome.