Table 5 Abnormal performance of the... | Emerald Publishing

Table 5

Abnormal performance of the decertification event (Group 2)

Decertification event study
Period	AP median	AP mean	Normality	Skewness	p-value (WSR)	p-value (sign test)
Labour productivity (operating income/number of employees)
t − 2 to t − 1	−115.00	2678.30	No	X	0.875	1.000
t − 1 to t	622.67	3264.57	No	X	0.379	0.641
t − 1 to t + 1	955.62	5297.52	No		0.046*	0.271
t − 1 to t + 2	1745.17	8665.25	No	X	0.007**	0.000***
Sales performance (yearly percentage change in industrial sales)
t − 2 to t − 1	−0.53%	−0.48%	No		0.582	0.932
t − 1 to t	1.62%	1.17%	No		0.671	0.646
t − 1 to t + 1	2.09%	1.43%	No		0.249	0.265
t − 1 to t + 2	−0.69%	0.65%	No	X	0.897	0.797
Profitability (return on assets)
t − 2 to t − 1	−0.24%	0.40%	No	X	0.655	0.668
t − 1 to t	0.52%	0.21%	No		0.267	0.461
t − 1 to t + 1	1.17%	1.02%	No		0.028*	0.002**
t − 1 to t + 2	0.89%	0.46%	No	X	0.236	0.106

Decertification event study
Period	AP median	AP mean	Normality	Skewness	p-value (WSR)	p-value (sign test)
Labour productivity (operating income/number of employees)
t − 2 to t − 1	−115.00	2678.30	No	X	0.875	1.000
t − 1 to t	622.67	3264.57	No	X	0.379	0.641
t − 1 to t + 1	955.62	5297.52	No		0.046*	0.271
t − 1 to t + 2	1745.17	8665.25	No	X	0.007**	0.000***
Sales performance (yearly percentage change in industrial sales)
t − 2 to t − 1	−0.53%	−0.48%	No		0.582	0.932
t − 1 to t	1.62%	1.17%	No		0.671	0.646
t − 1 to t + 1	2.09%	1.43%	No		0.249	0.265
t − 1 to t + 2	−0.69%	0.65%	No	X	0.897	0.797
Profitability (return on assets)
t − 2 to t − 1	−0.24%	0.40%	No	X	0.655	0.668
t − 1 to t	0.52%	0.21%	No		0.267	0.461
t − 1 to t + 1	1.17%	1.02%	No		0.028*	0.002**
t − 1 to t + 2	0.89%	0.46%	No	X	0.236	0.106

Note(s): *, ** and *** significant at 5, 1 and 0.1% levels, respectively (Benjamini-Hochberg's (1995) false discovery rate correction)