Table 4.

Decomposition of changes in retention rates over time

	RNs			Enrolled
	1999	1994	Differ.	1999	1994	Differ.
Sample Size	45084	41386		9374	9095
Observed mean retention probability	0.849	0.839	0.010	0.804	0.771	0.033
Predicted mean retention probability	0.849	0.839	0.010	0.804	0.771	0.033
Probability at mean characteristics:	0.857	0.848	0.009	0.813	0.781	0.031
Overall decomposition:
Contribution from differences in coefficients			0.006			0.030
Contribution from differences in mean characteristics			0.004			0.001
Total			0.009			0.031
Contribution from individual characteristics:
Personal characteristics (age, citizenship, sex)			0.002			0.012
Human capital (post basic qualification, years registered)			0.005			0.005
Location of job (region, unemployment rates)			-0.003			-0.003
Hours of work (hours in main job, second job as nurse)			0.003			-0.001
Job characteristics (classification, field, activity, premises)			-0.004			-0.012
Total			0.004			0.001
Characteristics whose coefficients changed significantly between 1994 and 1999:
RNs: sex, hours in main job, job classification, field and activity.
Enrolled: post-basic qualification and field

Notes: Separate probits are estimated for 1999 and 1994 and for RNs and enrolled nurses. In both years the same explanatory variables are used and differences in the predicted retention probability is decomposed using a first order Taylor-series expansion.