1. Segregation change: Longitudinal evidence from the NCDS and the ONS Longitudinal Study Dr Daniel Guinea-Martin Longitudinal Development Team Office for National Statistics

2. Introduction Aims Definitions Structural changes/changes in occupational classification Data –Comparing LS & NCDS cohorts Occupational segregation by sex in the 1990s –At the aggregated level –At the individual level The importance of data comparison Next steps

3. Aims To study occupational segregation by sex in England and Wales during the 1990s at both the aggregated and individual levels. To do so by using a variety of data sources. Why? So that they compensate each other’s weaknesses. –At the aggregated level: Census, ONS LS, LFS –At the individual level: ONS LS and NCDS.

4. Definitions Key concepts at the aggregated level: –Overall Segregation –Vertical Segregation (See Blackwell, L. and D. Guinea-Martin, ‘Occupational segregation by sex and ethnicity in England and Wales’, Labour Market Trends, December 2005, Vol. 113, No. 12, pp. 501-16 Key concept at the individual level: sex-typed occupations –Male occupations (0-29 % female) –Integrated occupations (30-69 % female) –Female occupations (70-100 % female)

5. 4 most male, integrated and female occupations in 1991 and 2001 (Unit Group Level)

6. Structural changes/changes in occupational classification from 1991 to 2001 ‘Tightening’ the application of the title ‘manager’ Increase in jobs related to information and communication technologies Recognition of growth of jobs related to, e.g., environmental protection/conservation, arts, media and sports/fitness. In manufacturing: Increase of technically qualified jobs /reduction of craft-related occupations Increase in sales and after-sales occupations and in occupations in call centres.

7. Data used (1) Census Longitudinal Study 1971 1981 1991 2001 + events 1991 2001 10 % x- section 100 % x- section n = 500,000 (late 1950s cohort n= 19,152) 1991 2001 n = 60,000 1996 LFS 1991 1999/2000 n = 17,415 /10,979 NCDS 1974 1981 1969 1965 1958

8. Comparing the LS and the NCDS The LS is used to assess the representativeness of the NCDS sample, with specific reference to the occupation-related variables. Levels of ‘attrition’ in the LS and NCDS cohorts –11.1 per cent lost-to-follow-up from 1991 to 2001 in the LS –12.8 per cent attrited from 1991 to 1999/2000 in the NCDS

9. Economic activity in 1991

10. Economic activity in 1999/2001

11. People in work by sex, cohort and year (II)

12. Occupation in 1991

13. Occupation in 2001

14. Number of sex-typed occupations (at unit groups level) by major groups in 1991 Census (SOC90)

15. Occupational sex segregation over time (standardised Gini indices) 1971 1981 1991 1996 2001 2001 (CO70) (CO80) (SOC90) (SOC90) (SOC2000) (SOC90) Census - - 0.78 - 0.69 - LFS - - 0.76 0.75 0.72 ONS LS 0.81 0.80 0.77 - 0.70 0.72 (no person imputation)

16. Occupational sex segregation over time for two cohorts born in late 1950s 1991 1999/2001 2001 (SOC90) (SOC90) (SOC2000) aged 31-34 aged 41-44 aged 41-44 NCDS Stan. Gini 0.80 0.80 Stan. MM 0.66 0.65 Index of Diss. 60.7 60.1 ONS LS Stan. Gini 0.78 0.77 0.76 Stan. MM 0.65 0.62 0.62 Index of Diss. 59.4 57.1 56.9

17. Occupations making most difference between LS&NCDS cohorts in 1999/2001

18. Sex by sex-typed occupations in 1991 and 2001 (Column percentages)

19. Next steps Using the strength of the NCDS: work histories Apply Survival Analysis to study the influence of sex-type of occupation on duration in employment: – How long people stay on an occupation depending on what sex-type of occupation it is?