The top half of Table 5 includes absolute estimation bias, standard error estimates, and coverage rates for [gamma].sub.00] by method of estimation and percent of outlying observations
, averaged across the other study variables.
In particular, extreme points, influential and outlying observations
, which might represent erroneous data or otherwise reflect unusual market conditions such as non-arm's length transactions, can seriously undermine the performance of parametric estimator.
Preliminary inspection of these results indicated the possible existence of extreme outlying observations
(Table S1 of the online Data Supplement).
Two new organizations in the sample were so large that, in statistical terms, they were outlying observations
. Therefore, consideration was given to excluding them from the sample.
The estimation of the regression function values for the ranges is an iterative process with minimization of the influence of the most outlying observations
The equation explains about 70 per cent of labour demand over this period, with only a few outlying observations
on the downside during the recessions of 1973-5 and 1981-2.