6.2 Comparing the Election Study occupation results with similar overseas studies

Table 8 compares intergenerational occupational mobility in New Zealand using Election Study data to the results for a similar study of Britain and Germany (Ermisch, et al., 2006, pp. 666-669). Figure 3 summarises the results in a graph, with the solid bars showing the effect of a one unit change in father’s SES.[38] The thin black lines show the 90% confidence intervals.[39] Additional information on the data for each country is available in Table A12 in the Appendix.

Figure 3 suggests that men and women in New Zealand aged 25 years or over had slightly higher intergenerational occupational mobility than people 25 years or older in Britain. The evidence is weak, however, as this difference was barely significant at a 10% level. Men in New Zealand also had higher occupational mobility than men 25 years or older in Germany. This difference was statistically significant at a 5% level, which provides reasonably strong evidence of a difference in occupational mobility. Although our point estimate for New Zealand women is lower than the point estimate for German women, the 90% confidence intervals overlapped indicating the difference is insignificant even at a 10% level.

In Britain and Germany, however, the standard deviations for respondents' ages suggest respondents were born within a narrower time-period than in New Zealand (Ermisch, et al., 2006, p. 668). There may be other methodological differences we are unaware of. We should therefore be cautious when comparing the results for New Zealand in Figure 3 with those for Britain and Germany.

Our point estimate for New Zealand men is very similar to an unpublished intergenerational occupational mobility point estimate for New Zealand men in an overseas study (Blanden, 2008, p. 34). That study suggested that New Zealand had high intergenerational occupational mobility compared to other countries, with New Zealand placed third out of 32 countries. Confidence intervals were not included, so we cannot ascertain whether differences were statistically significant (Blanden, 2008, p. 34). There is therefore still considerable uncertainty about how New Zealand compares to other countries in terms of intergenerational occupational mobility.

A low coefficient indicates that father's SES has a low effect on the SES of their adult children, and indicates high intergenerational occupational mobility. Whereas this table lists 95% confidence intervals, Figure 3 shows 90% confidence intervals.

Figure 3 - Intergenerational occupational mobility estimates for those 25 years and over in Britain, Germany and New Zealand (with 90% confidence intervals)

A low coefficient indicates that father's SES has a low effect on the SES of their adult children, and indicates high intergenerational occupational mobility. The parameter estimates for men are in blue, and for women are in orange. The thin black lines show the 90% confidence intervals. As 90% confidence intervals are narrower in range than 95% confidence intervals they are less likely to include the true population parameter.