lated with industry (r = 0.20) with service
sector being more diverse than production.
The general hypothesis was tested by
conducting a hierarchical regression analysis
(Cohen and Cohen, 1975, see Table 2). The
results indicated that only industry has a significant
impact on ROI at time 2 in the first
step of the regression analysis (t = -4.37; p <
0.01). This suggested that the production firms
were able to get better ROI than service firms
during this time period. In the second step,
board diversity had a significant impact on
ROI at time 2 when controlling for ROI at time
1 (F = 13.46; p < 0.01).
Similar results were found with ROA, with
some changes in regards to the control variables.
Both ROA time 1 and industry had a significant
impact on ROA at time 2 (t = 2.76 and
t = -3.52, respectively). Board diversity had a
significant impact on ROA at time 2 (F = 8.59;
p < 0.01). The results of this study supported
the original hypothesis stating that relatively
higher levels of board diversity would lead to
higher organisational performance.