Cross-sectional data

	Summarizing the data

For each individual, we can sum the number of migrations recorded in the survey, to produce one line of information containing:

	Case number
	Number of migrations since leaving school (n)
	Time (t), number of years since leaving school

Only time independent explanatory variables are included in these cross-sectional data.

	Educational qualification (ed), with 5 levels:
	1=Degree or equivalent; professional qualifications with a degree
	2=Education above A-level but below degree level; includes professional qualifications without a degree
	3=A-level or equivalent
	4=Other educational qualification
	5=None

The data matrix for the individual shown on the longitudinal data page can be summarized as follows:

This person is one of the eight in the data set to have 5 migrations during the time in the survey. See Table 1.
The data sets can be downloaded from here. The cross-sectional data set is available in the file rochmigx.dat.

	TABLE 1: Observed migration frequencies

Table 1 summarizes the observed migration frequencies for the 348 respondents in the sample.

As the individuals ranged in age from 20 to 60, they had varying lengths of migration history.