UPDATE – News from the LS User Group ISSN 1465-8828 Issue no. 24 April 2000 __________________________________________________________________ Contents 1 Page Diary LS Workshop 2 2 Using the LS for International Research Report on the 1999 LS User Group meeting 3 2 Technical Issues Migration between counties among LS members born in the 1930s 4 5 8 LS Publications LS Working Paper on teenage fertility in England and Wales 14 LS Working Paper on identifying area effects 14 Staff Changes at CLS 14 This newsletter is designed to provide information on the ONS Longitudinal Study (LS) and a forum for the exchange of users' views and comments. It is produced by the LS User Support Programme at the Centre for Longitudinal Studies (CLS), Institute of Education. All comments and contributions should be sent to Rosemary Creeser, LS User Support Programme, Centre for Longitudinal Studies, Institute of Education, 20 Bedford Way, London WC1H 0AL (tel: 020 7612 6877 email: rc@cls.ioe.ac.uk) 1 1 Diary This section highlights forthcoming events of interest to LS Users. If you are arranging an event and wish to publicise it in Update please send details to Dina Maher, the LS Administrator at CLS. LS Workshop On Wednesday 27 th/Thursday 28th September 2000 the LS User Support Programme will be holding a 2-day LS workshop. LS workshops provide detailed information on the ONS Longitudinal Study, and the methods of analysis and software available to LS researchers. They are also an ideal opportunity to meet members of the LS Support Team and to discuss the suitability of the LS for exploring specific research questions. As part of the hands-on element of the workshop participants are able to specify an analysis of their choice using a small sub-set of variables from the LS. While LS workshops are open to all, places are limited to ensure that participants get sufficient individual attention and hands-on experience. A non-refundable fee of £50 (£20 for students) is charged to cover documentation, lunch and refreshments. For further details and to reserve a place please contact LS Administrator Dina Maher (tel: 020 7612 6875, email: dm@cls.ioe.ac.uk). 2 Using the LS for international research Report on the 1999 LS User Group Meeting On 9th November the Institute of Education hosted the 1999 LS User Group meeting. While countries around the world were commemorating the tenth anniversary of the end of the Berlin Wall a group of researchers from Cyprus, Finland, Germany, Norway, Sweden, the United States and the UK were meeting to consider how the LS may be used for cross-national work. Some of the main points of the meeting are summarised below. Copies of several of the papers given at the meeting are also available in .PDF (Portable Document Format) from the CLS website – http://www.cls.ioe.ac.uk/Ls/user.htm Introduction to using the LS for international research: Rosemary Creeser, LS User Support Team, CLS This session highlighted the opportunities that exist for using the LS for international comparative research. In addition to national studies based on linked census and mortality data, some countries like Austria and Israel have data based on one-off census link exercises, while others like Italy have studies that bring together data for a particular region (e.g. the municipality of Turin). While many countries in Europe and Scandinavia maintain studies similar to the LS it is important to remember that national studies have not necessarily been designed to facilitate international comparative research. Table 1 summarises some of the advantages of the LS for this type of work. One of the distinctive features of the LS is that data are available in their raw, uncoded form. Consequently, they are easier to recode to classifications developed to facilitate international comparisons, than data that have been aggregated or “top coded”. 2 Table 1: Advantages of the LS for international comparative research “Safe setting” Data maintained in raw, disaggregated form. Harmonised variables Variables derived as part of previous research, such as work on the “English and French family in historical perspective” available for future research. Data Expertise Staff at LS User Support Programme (CLS, Institute of Education) and LS Unit (ONS) are able to share data expertise and facilitate access to the LS. Unfortunately, one of the real obstacles to international comparative research is that few of the countries with similar datasets are able to offer the high level of user support and access offered by the LS. LS researchers are able to draw on the CLS and ONS teams’ experience of analysing this complex dataset and to obtain expert advice on a large number of variables specially derived for international research. The relationship between fertility and longevity in England and Wales and Austria: Gabriele Doblhammer, Max Planck Institute for Demographic Research Rostock, Germany Gabriele Doblhammer's presentation focused on work she has undertaken using the LS and a linked dataset based on the 1981 Census returns of 1.3 million Austrian women, between the ages of 40 and 59, and the death records of 32,234 who died in the following year. This work seeks to address whether a woman's reproductive history influences her life span. A leading biological theory of the evolution of ageing suggests that resources have to be directed either towards maintenance and repair or reproduction. Issues of comparability and data quality In international cross-national work it is important to achieve comparability. One of the main variables investigated in Gabriele's work - the woman's parity - was relatively simple to compare. The recording of parity in both datasets would have been affected by similar problems - e.g. women may omit to include children born outside marriage or still-births etc. By comparison, Gabriele experienced some problems finding comparable data on education - one of the explanatory variables she considered. While the Austrian dataset included good measures of education, currently the educational data a vailable in the LS focus exclusively on the "higher" educational qualifications obtained by less than twenty per cent of the population. (As mentioned in issue 22 of Update , new proposals for the 2001 Census include collecting information on all of the educational and vocational qualifications achieved, including GCSE (General Certificate of Secondary Education) and NVQ (National Vocational Qualifications).) The Austrian data were linked using date of birth and the municipality code of the last residential address of the deceased. While 92 per cent of death records were linked, there were some sub-national differences. The higher linkage rate for rural areas, such as Burgenland (94 per cent), compared with Vienna (88 per cent) reflect differences in the likelihood of individuals moving into residential care in the last few years of life. (Those living in rural areas are more likely to be living with their adult children at both time points.) 3 Results/discussion This work shows that there is a significant relationship between parity and mortality later in life in both populations. Childless women and women with higher parities (3+) experience higher mortality risks than women with one or two children (see Table 2). The Austrian data reveal that women experience significant excess mortality from the fourth child on. Table 3 shows that having a teenage birth some years before significantly increases the risk of mortality later in life in both populations. While the proportion of English/Welsh women who gave birth before age 20 is only half that of Austrian women, the excess mortality observed in the LS is nearly three times as high (26 per cent) as in the Austrian dataset (9 per cent). One possible explanation may be that the negative social circumstances that may have been related to giving birth comparatively early in life were more severe in England and Wales than in Austria, where the phenomenon is more widespread. The study also shows a positive relationship between giving birth after age 40 and longevity, which is consistent with the findings of previous studies (Perls et al, 1997). An examination of the Austrian data suggest that the longevity advantage of late mothers results from a reduction in the risk from circulatory diseases, although their risk of breast cancer is significantly increased. One possible explanation may be that a late birth is a biological marker that these women have aged at a slower rate and that their menopause occurred comparatively late. References: Doblhammer, G. (1999) Reproductive history and mortality later in life: a comparative study of England and Wales and Austria, Max Planck Institute for Demographic Research Working Paper WP 1999-004 (April 1999), Rostock: Max Planck Institute for Demographic Research Perls, T. T ., Alpert, L. and Fretts, R.C. (1997) “Middle aged mothers live longer”, Nature, 389, page 133 4 Table 2: Relative mortality risks (RMR) by parity: Austria ages 50-94, England and Wales ages 50-85 England and Wales1 Austria 2 Parity RMR Parity RMR 0 1.15*** 0 1.15*** 1+2 (RG) 1.00 1 1.01 3+ 1.07*** 2 (RG) 1.00 3 1.02 4 1.06** 5+ 1.10*** Education Education High (RG) 1.00 High (RG) 1.00 Medium 1.36*** Medium 1.16*** Basic 1.71*** Basic 1.38*** Family Status Married (RG) 1.00 Widowed 1.27*** Divorced 1.39*** *** significant at the 99 per cent level; ** significant at the 95 per cent level RG: Reference group Source: Doblhammer (1999) Table 3: Relative mortality risks (RMR) by parity, age at first birth and birth after 40: Austria ages 50-94, England and Wales ages 50-85 England and Wales1 Austria Parity RMR Parity RMR 1+2 (RG) 1.00 1 1.01 3+ 1.06*** 2 (RG) 1.00 3 1.02 4+ 1.06*** Age at first birth Age at first birth <20 <20 20+ (RG) 20+ (RG) Birth above age 40 No (RG) Yes Birth above age 40 No (RG) Yes 4th birth < 40, age at birth 5+ unknown Education Education High (RG) 1.00 High (RG) Medium 1.39*** Medium Low 1.74*** Low Family Status Married (RG) Widowed Divorced *** significant at the 99 per cent level; ** significant at the 95 per cent level; * significant at the 90 per cent level. RG: Reference group Source: Doblhammer (1999) 1 2 1.00 0.95* 1.00 0.95** 1.09 1.00 1.22*** 1.43*** 1.00 1.24*** 1.36*** The LS data cover deaths occurring in the period 1971-96 to women enumerated at the 1971 Census. Austrian data cover all deaths in the year after the 1981 Census. 5 Using the LS for monitoring health inequalities in the EU, Anton Kunst, Department of Public Health, Erasmus University, Rotterdam Anton Kunst focused on the practicalities of doing international research, such as getting data from different countries and the problems of achieving comparability. His presentation draws upon over ten year’s experience of using LS data to study socio-economic inequalities in health. Figure 1 summarises the three different ways in which access to data may be negotiated. This shows, for example, that data from the National Centre for Health Statistics (NCHS) are available in public-use files. By comparison, data from Statistics Finland are accessed via a research team based in the Sociology Department of the University of Helsinki. Figure 1: Three forms of access to data in a specific country Erasmus University University of Helsinki, Finland NCHS (USA) Statis tics Finland ONS Anton mentioned that comparability problems crop up at different stages of the research project. A good example is the range of different socio-economic classifications: different patterns may apply according to the scheme that is used. Table 4 shows the different patterns that appear when two different conversion algorithms were used. Table 4: Mortality of skilled and unskilled workers: estimates based on two conversion algorithms Sweden, 1980-1986, men ages 45-59 in 1980 SMRs estimated by EGP 3 algorithm Skilled workers Cause of death All causes Lung cancer Ischemic heart disease Cerebrovascular disease Respiratory disease Gastrointestinal disease External causes of death 3 4 Unskilled workers 121 135 121 120 138 133 133 105 111 106 92 104 96 110 SMRs estimated by GLT 4 algorithm Skilled workers 111 118 111 103 127 103 124 EGP=Erikson, Goldthorpe and Portocarero. See Erikson, Goldthorpe and Portocarero (1983) GLP=Ganzeboom-Luijkx-Treiman. See Ganzeboom and Treiman, Donald (1996) 6 Unskilled workers 116 134 117 112 115 131 117 Using the EGP (Erikson, Goldthorpe and Portocarero) algorithm the mortality of unskilled workers is consistently higher than that of skilled workers. However, using the GLT (Ganzeboom-Luijkx-Treiman) algorithm for some causes of death skilled workers appear to have higher mortality than unskilled workers. This variation occurs as some occupations are allocated to different groups under the two classification schemes. Anton considered why researchers would want to undertake international comparative research. He came up with four explanations, which are particularly relevant to the international health inequalities work he is involved in. Figure 2: Why compare countries with respect to health inequalities? 1. Judgement: comparative work provides a yardstick to judge the health inequalities in your own country. 2. Explanation: identifies factors that are associated with larger or smaller health inequalities – e.g. smoking, diet, alcohol intake etc. 3. Policy: to study other countries as “natural experiments” in reducing health inequalities. 4. Exchange: to assess whether research findings from one country can be extrapolated to other countries. In the discussion that followed this presentation a member of the audience raised the issue of accessing data from countries in Southern Europe, such as Portugal and Spain. Anton confirmed that the Erasmus University research team used published data from these countries statistical offices, comparable to the England and Wales decennial supplements. They also used data from sub-national census-link studies – such as the study based on the Turin municipality. References: Erikson, R, Goldthorpe, J.H. and Portocarero (1983) “Intergenerational mobility and the convergence thesis”, British Journal of Sociology, 34 , pp 303-340 Ganzeboom, H.B.G, Treiman, D.J. (1996). "Internationally comparable measures of occupational status for the 1988 International Standard Classification of Occupations". Social Science Research , (25) , pp 201-239 One-person households and migration in France and England and Wales: some comparative evidence from censuses and longitudinal sources: Ray Hall and Philip Ogden, Department of Geography, Queen Mary and Westfield College, University of London Ray Hall and Philip Ogden’s presentation focused on work they have undertaken on the impact of migration and living alone. Their research uses migration histories for adults under retirement age – the group that has shown the greatest increase in the number of people living alone – and draws upon data from the LS, the Echantillon Démographique Permanent (EDP) and specially commissioned tables from the French census. This type of demographic comparison is useful for highlighting differences and similarities and also gives perspective on the patterns seen in England and Wales. For this particular project the researchers were more interested in identifying trends in the two countries – rather than making direct comparisons. Ray Hall highlighted that, compared with the LS, arrangements for accessing the EDP are less comprehensive. For this project Philip Ogden carried out the French analyses from the offices of INSEE (Institut National de la Statistique et des Etudes Economiques) in Paris. By comparison, the LS receives funding from both the Economic and Social Research Council (ESRC) and the Office for National 7 Statistics (ONS). This facilitates a number of access arrangements – including the option of obtaining small sub-sets of data in machine-readable form. Ray confirmed that despite the fact that the EDP is less well resourced than the LS it can be successively used for international comparative work. However, LS researchers need to be aware of the differences between the two studies (for example, the LS migration data they used is based on a comparison of EDcentroids whereas the French migration data draws on questions asked at the census) and to make appropriate adjustments to the LS data. Possible uses of the LS and EDP on fertility: Michael Rendall, Population Research Institute, Penn State University, USA Michael Rendall’s presentation considered some of the similarities and differences of the LS and the EDP (Echantillon Démographique Permanent) or French demographic panel, with particular reference to fertility studies. The EDP has much in common with the LS – both in the type of data that are recorded and the period covered. Currently, the EDP includes census data from 1968 to 1990 and data from birth registration up to 1995. (Since 1982 birth registration data have only been linked into the EDP for half of the women in the study.) Overall linkage rates are correspondingly high (around 85%) in both countries for the periods since the last census. While LS data are maintained as a hierarchical multi-file database, the French data are held in a flat file. While this makes the EDP easier to use, compared with the LS, the French data allow for little description of the census household. Also there is no French equivalent to the data on fertility history, recorded at the 1971 Census, which has proved useful for studies of inter-generational effects. Michael’s research on comparisons of teenage fertility focuses on the birth records of two cohorts (LS members born between 1972-78 and members of the EDP born 1969-1975). Preliminary results show that in both countries teenage girls are 2 to 2.5 times more likely to give birth if their mother was a teen mother. However, by comparison with England and Wales where the rates haven’t changed much, in France levels of teen childbearing in the 1990s are three times lower than in Britain. Work is currently underway to build a projection model of inter-generational teen and non -teen childbearing in both countries. It is hoped that this will highlight the importance of repetition of teen childbearing across generations of mothers and daughters for explaining the divergence in teen childbearing in the two countries. 3 Technical Issues Migration between counties among LS members born in the 1930s: a study of three time points (1939, 1971 and 1991) David Strachan, Department of Public Health Sciences, St George's Hospital Medical School, Brian Dodgeon, LS User Support Programme, Centre for Longitudinal Studies, Institute of Education An earlier contribution to Update (Dodgeon, 1998) described how the alphabetic stem of the National Health Service number has been used to determine where LS members were enumerated in the wartime National Register compiled on 29 September 1939. This article uses these areas of enumeration to examine patterns of migration between 1939 and 1991. The LS variable POBPOB provides a mapping of 1939 areas of enumeration onto post-1974 counties. We examined this in relation to the areas of residence at census in 1971 and 1991, also classified by the 8 post-1974 boundaries. The analysis was limited to 39,409 LS members who were born 1 January 1930 to 29 September 1939, resident in England and Wales at the 1971 and 1991 censuses, and have POBPOB codes indicating a county of England or Wales at National Registration. This group is 70 per cent of all 56,580 LS members born 1 January 1930 to 29 September 1939. Over half of the cohort (22,085 individuals or 56 per cent) of the cohort were coded to the same county in 1939, 1971 and 1991. Although these may have migrated within the county, or moved out of the county transiently within each time interval, they are considered for the purposes of this analysis as "nonmigrants". The pattern of movement among the remainder (the "migrants") was as follows: • • • • 10,711 (27 per cent of 39,409) changed county between 1939 and 1971, but not from 1971 to 1991. 2,320 (6 per cent of 39,409) changed county between 1971 and 1991, but not from 1939 to 1971. 906 (2 per cent of 39,409) changed county between 1939 and 1971, but had returned to their 1939 county by 1991. 3,387 (9 per cent of 39,409) c hanged county in both time intervals, and were living in a different county in 1991 from their county of enumeration in 1939. Table 5 shows the pattern of inter-county migration during three time periods (1939 to 1971, 1971 to 1991, and 1939 to 1991) for groups defined by their county of enumeration in 1939. The proportion of migrants during 1939 to 1971 tends to be highest in the "home counties" – e.g. Bedfordshire, Berkshire, Buckinghamshire, Hertfordshire and Surrey. This may reflect in part the impact of evacuation of children from London to surrounding rural areas during the first few weeks of the war. However, there is also substantial mobility from other areas (including Greater London itself). Furthermore, cohort members who were enumerated in the home counties in 1939 were also more mobile than average during 1971 to 1991. Tables 6 and 7 provide equivalent breakdowns, based on county of residence at the 1971 Census (Table 6) and 1991 Census (Table 7). The pattern of greater mobility in the south of England than in the north of England and Wales is evident throughout. These preliminary analyses provide an insight into the potential for research based on this "additional time point" within the LS. The socio-economic characteristics of inter-regional migrants from 1939 to 1971 have been reported elsewhere (Leon and Strachan, 1993) but with a third time point and a finer geographical breakdown by county, there is scope for a more detailed analysis. Migrants are of particular interest in distinguishing critical periods of influence of environmental factors on human development. We have published earlier the effects of interregional migration on cardiovascular mortality among all LS members who were enumerated in 1939 (Strachan, Leon and Dodgeon, 1995). In that analysis, 1939 area of enumeration related to different periods of life for different birth cohorts of LS members. The advantage of concentrating on LS members born in the 1930s is that area of enumeration is a marker for childhood environment, which is of special interest in the "life course" approach to epidemiology (Kuh and Ben -Schlomo, 1997). However, the specific disadvantage of the wartime register is that many children were evacuated from major cities during the first week of September 1939 in anticipation of immediate bombing raids (Holman, 1995; Inglis, 1989). Under official schemes, 826,959 unaccompanied schoolchildren and 536,670 children with mothers were evacuated during September 1939 (Holman, 1995). The proportion of schoolchildren evacuated was highest in London (approximately 50 per cent), Manchester, Liverpool and Newcastle (approximately 60 per cent) and the West Midlands (approximately 25 per cent), and over half of these had not returned home by January 1940. Although a lower proportion of pre-school children were evacuated, these massive population movements need to be considered when interpreting the LS data for 1930-1939 birth cohorts. 9 Some insight can be obtained by comparing the distribution of Barker (Dodgeon, 1998) geographical codes in the LS sample and the distribution of births (surviving to 1 year of age) across the same 229 local government areas during the 1930s. In summary, the percentage distributions are: % LS born 1930-39 Inner London boroughs "Other city centres"* Other county boroughs Municipal & urban districts Rural districts % births 1930-38# 3.4% 5.9% 24.3% 42.2% 24.2% 9.7% 8.1% 26.1% 37.2% 19.0% # Live births minus infant deaths by geographical area. No data published for 1939. * Birmingham CB, Liverpool CB, Manchester CB and Newcastle CB. The apparent deficit of LS members enumerated in the city centres is a manifestation of two influences: slum clearance and surburban development, primarily in urban districts, throughout the 1930s; and early wartime evacuation, primarily to rural districts. Although both will tend to reduce the differences between urban and rural areas, this dilution effect is not overwhelming: for instance the population of LS members enumerated in the rural districts is inflated by about one-quarter, relative to the distribution of births. The equivalent excess in municipal and urban districts is about one-seventh. Further work may be required to investigate local discrepancies between the distribution of births and LS members enumerated in 1939. However, we conclude that the 1939 area codes can be used with caution to investigate patterns of migration within the LS and the effect of early environment on experiences later in life. References: Dodgeon, B. (1998) “Barker geographical codes”, Update - News from the LS User Group , Issue 2 (November 1998), page 3 Holman, B. (1995) The evacuation: a very British revolution, Oxford: Lion Publishing, pp 8-29 Inglis, R. (1989) The children's war: evacuation 1939-1945 . London: Collins Kuh, D. and Ben-Shlomo, Y. (1997) (eds) Life course influences on adult disease. Oxford: OUP Leon, D.A. and Strachan, D.P. (1993) “Socio-economic characteristics of inter-regional migrants in England and Wales 1939-71”, Environment and Planning A, 25, pp 1441-1451 Strachan, D.A., Leon, D.A. and Dodgeon, B. (1995) “Mortality from cardiovascular disease among interregional migrants in England and Wales”, British Medical Journal , 310, pp 423-427 10 Table 5: Pattern of inter-county migration for LS members born 1930-39, by area of enumeration in 1939 (classified to post-1974 county boundaries) County in 1939 Total Greater London Greater Manchester Merseyside South Yorkshire Tyne and Wear West Midlands West Yorkshire Avon Bedfordshire Berkshire Buckinghamshire Cambridgeshire Cheshire Cleveland Cornwall Cumbria Derbyshire Devon Dorset Durham East Sussex Essex Gloucestershire Hampshire Hereford and Worcs Hertfordshire Humberside Isle of Wight Kent Lancashire Leicestershire Lincolnshire Norfolk Northamptonshire Northumberland North Yorkshire Nottinghamshire Oxfordshire Shropshire Somerset Staffordshire Suffolk Surrey Warwickshire West Sussex Wiltshire Clwyd Dyfed Gwent Gwynedd Mid Glamorgan Powys South Glamorgan West Glamorgan All counties 4404 2178 1459 1371 1065 2243 1752 690 356 407 347 418 682 475 307 530 923 694 423 769 618 801 451 810 518 572 785 90 1043 1201 615 491 608 397 330 605 827 377 288 385 862 503 695 317 494 386 346 347 476 232 643 131 313 359 39409 Migrants 39-71 Migrants 71-91 Migrants 39-91 Number %total Number %total Number %total 2127 549 430 358 295 622 411 226 169 217 190 172 223 92 114 183 306 288 230 330 392 344 229 281 248 289 219 50 434 451 167 196 232 183 164 303 211 174 109 185 215 247 412 113 324 186 166 140 159 113 254 60 109 113 15004 48 25 29 26 28 28 23 33 47 53 55 41 33 19 37 35 33 42 54 43 63 43 51 35 48 51 28 56 42 38 27 40 38 46 50 50 26 46 38 48 25 49 59 36 66 48 48 40 33 49 40 46 35 31 38 11 1207 306 207 165 139 403 224 98 76 72 74 79 89 57 45 51 148 136 86 100 131 140 76 136 83 134 87 14 157 165 78 63 88 60 47 88 109 67 32 76 109 86 186 51 123 71 54 47 68 44 79 10 49 43 6613 27 14 14 12 13 18 13 14 21 18 21 19 13 12 15 10 16 20 20 13 21 17 17 17 16 23 11 16 15 14 13 13 14 15 14 15 13 18 11 20 13 17 27 16 25 18 16 14 14 19 12 8 16 12 17 2679 661 498 394 329 807 476 229 198 228 205 181 233 111 108 190 337 283 226 335 402 355 234 304 242 310 234 52 447 458 185 198 221 195 164 295 235 190 111 194 236 249 447 118 324 191 158 136 167 107 251 60 121 119 16418 61 30 34 29 31 36 27 33 56 56 59 43 34 23 35 36 37 41 53 44 65 44 52 38 47 54 30 58 43 38 30 40 36 49 50 49 28 50 39 50 27 50 64 37 66 49 46 39 35 46 39 46 39 33 42 Table 6: Pattern of inter-county migration for LS members born 1930-39, by area of residence in 1971 (classified to post-1974 county boundaries) County in 1971 Total Greater London Greater Manchester Merseyside South Yorkshire Tyne and Wear West Midlands West Yorkshire Avon Bedfordshire Berkshire Buckinghamshire Cambridgeshire Cheshire Cleveland Cornwall Cumbria Derbyshire Devon Dorset Durham East Sussex Essex Gloucestershire Hampshire Hereford and Worcs Hertfordshire Humberside Isle of Wight Kent Lancashire Leicestershire Lincolnshire Norfolk Northamptonshire Northumberland North Yorkshire Nottinghamshire Oxfordshire Shropshire Somerset Staffordshire Suffolk Surrey Warwickshire West Sussex Wiltshire Clwyd Dyfed Gwent Gwynedd Mid Glamorgan Powys South Glamorgan West Glamorgan All counties 4414 2173 1343 1233 1055 2081 1682 721 403 509 447 455 841 542 305 424 830 647 374 572 409 1258 415 1132 464 839 766 76 1137 1107 653 461 537 361 240 533 875 409 300 352 974 445 839 427 508 444 280 277 407 180 501 109 311 332 39409 Migrants 39-71 Migrants 71-91 Migrants 39-91 Number %total Number %total Number %total 2137 544 314 220 285 460 341 257 216 319 290 209 382 159 112 77 213 241 181 133 183 801 193 603 194 556 200 36 528 357 205 166 161 147 74 231 259 206 121 152 327 189 556 223 338 244 100 70 90 61 112 38 107 86 15004 48 25 23 18 27 22 20 36 54 63 65 46 45 29 37 18 26 37 48 23 45 64 47 53 42 66 26 47 46 32 31 36 30 41 31 43 30 50 40 43 34 42 66 52 67 55 36 25 22 34 22 35 34 26 38 12 1319 282 174 111 102 359 174 91 113 132 145 93 141 64 43 24 108 85 52 58 82 224 67 245 71 217 75 14 170 117 94 67 54 60 32 70 103 105 44 57 144 61 244 83 106 93 24 25 37 22 47 10 47 32 6613 30 13 13 9 10 17 10 13 28 26 32 20 17 12 14 6 13 13 14 10 20 18 16 22 15 26 10 18 15 11 14 15 10 17 13 13 12 26 15 16 15 14 29 19 21 21 9 9 9 12 9 9 15 10 17 2648 663 384 265 321 646 418 268 241 315 295 211 378 172 107 91 238 253 186 153 205 817 192 614 198 580 216 37 542 379 222 159 161 157 80 223 284 209 124 157 343 188 588 220 340 242 97 70 104 61 117 36 116 87 16418 60 31 29 21 30 31 25 37 60 62 66 46 45 32 35 21 29 39 50 27 50 65 46 54 43 69 28 49 48 34 34 34 30 43 33 42 32 51 41 45 35 42 70 52 67 55 35 25 26 34 23 33 37 26 42 Table 7: Pattern of inter-county migration for LS members born 1930-39, by area of residence in 1991 (classified to post-1974 county boundaries) County in 1991 Total Greater London Greater Manchester Merseyside South Yorkshire Tyne and Wear West Midlands West Yorkshire Avon Bedfordshire Berkshire Buckinghamshire Cambridgeshire Cheshire Cleveland Cornwall Cumbria Derbyshire Devon Dorset Durham East Sussex Essex Gloucestershire Hampshire Hereford and Worcs Hertfordshire Humberside Isle of Wight Kent Lancashire Leicestershire Lincolnshire Norfolk Northamptonshire Northumberland North Yorkshire Nottinghamshire Oxfordshire Shropshire Somerset Staffordshire Suffolk Surrey Warwickshire West Sussex Wiltshire Clwyd Dyfed Gwent Gwynedd Mid Glamorgan Powys South Glamorgan West Glamorgan All counties 3352 2037 1238 1191 1011 1815 1614 733 373 506 444 485 865 512 432 478 844 856 521 579 494 1291 439 1140 555 822 780 97 1207 1184 652 543 641 405 256 647 862 391 346 403 957 503 850 433 598 463 342 315 427 229 500 123 295 333 39409 Migrants 39-71 Migrants 71-91 Migrants 39-91 Number %total Number %total Number %total 1654 504 287 216 271 399 337 264 196 298 258 212 362 146 177 118 226 387 274 155 242 751 210 586 233 516 206 43 529 388 189 200 222 176 81 287 254 191 140 174 291 222 521 204 389 253 125 93 116 82 112 46 101 90 15004 49 25 23 18 27 22 21 36 53 59 58 44 42 29 41 25 27 45 53 27 49 58 48 51 42 63 26 44 44 33 29 37 35 43 32 44 29 49 40 43 30 44 61 47 65 55 37 30 27 36 22 37 34 27 38 13 257 146 69 69 58 93 106 103 83 129 142 123 165 34 170 78 122 294 199 65 167 257 91 253 162 200 89 35 240 194 93 149 158 104 48 184 90 87 90 108 127 119 255 89 196 112 86 63 57 71 46 24 31 33 6613 8 7 6 6 6 5 7 14 22 25 32 25 19 7 39 16 14 34 38 11 34 20 21 22 29 24 11 36 20 16 14 27 25 26 19 28 10 22 26 27 13 24 30 21 33 24 25 20 13 31 9 20 11 10 17 1627 520 277 214 275 379 338 272 215 327 302 248 416 148 233 138 258 445 324 145 278 845 222 634 279 560 229 59 611 441 222 250 254 203 90 337 270 204 169 212 331 249 602 234 428 268 154 104 118 104 108 52 103 93 16418 49 26 22 18 27 21 21 37 58 65 68 51 48 29 54 29 31 52 62 25 56 65 51 56 50 68 29 61 51 37 34 46 40 50 35 52 31 52 49 53 35 50 71 54 72 58 45 33 28 45 22 42 35 28 42 4 LS publications LS Working Paper 78: Teenage fertility in England and Wales: trends in socio-economic circumstances between the 1971 and 1981 Censuses Michael Rosato, Central Health Outcomes Unit, London School of Hygiene and Tropical Medicine This working paper explores trends in teenage fertility between two periods after the 1971 and 1981 Censuses. The role of social mobility in the generation of these trends is also examined. Gradients associated with housing tenure became steeper between the two periods of interest, dominated by increased relative risks associated with Local Authority tenure. Indicators of family structure (the age of the LS teenager’s mother and the number of siblings) continue to show significant independent associations with the risk of teenage pregnancy. LS Working Paper 79: Identifying area effects: a comparison of single and multi-level models Simon Gleave, Richard Wiggins, Heather Joshi and Kevin Lynch, Centre for Longitudinal Studies, Institute of Education and Sociology Department, City University This paper explores whether multi-level models are more sensitive to a relationship between the incidence of limiting long-term illness and area deprivation at ward level that was seen in the single level analysis undertaken by Sloggett and Joshi using deprivation indicators for 1971 and 1981. The present authors were also able to use a ward deprivation index for 1991. The single level method can only reveal spatial effects associated with variables in the model but the multilevel approach also reveals area variation in unmeasured heterogeneity. The broad conclusion that individual effects are more important than area effects remains, but this paper has produced better estimates of the relatively minor effects of area. LS Working Papers are available from the LS User Support Programme (price £3). To obtain a copy of these and other LS Working Papers contact LS Administrator Dina Maher (tel: 020 7612 6875, email: dm@cls.ioe.ac.uk). 5 Staff Changes at CLS Since the beginning of the year there have been a number of changes in the composition of the LS User Support Team at CLS. At the end of March 2000 Simon Gleave, who has been working on the LS since 1991, left to take up a post in the Netherlands. We would like to thank Simon for his valuable contribution to the team and to wish him the best of luck in his new career. In January 2000 Sarah Jones joined the LS Team, closely followed by Angela Brassett-Grundy and Andrew Cullis, who joined in March. Sarah, who has a degree in Statistics and French from Coventry University is one of the key researchers on the ESRC-funded project “The Longitudinal Study after 2001: preparing for continuity”. Angela, who has a B.Sc. (Hons) in Psychology, previously worked as a Research Officer and IT Manager at the Association of Colleges. Before joining CLS Andrew, worked as a Senior Lecturer in the School of Service Industries at Bournemouth University. Each of the new team members will be providing research support/advice and helping to update and develop new LS documentation. 14