Study Number 5151 - British Household Panel Survey: Waves 1-18, 1991-2009

NEW EDITION INFORMATION

Since the first deposit of BHPS, materials from successive waves have been added each year. Longstanding users should note that before 2005, the BHPS may have had a different UKDA study number, hence the discrepancy between the edition number and the current survey wave.

• For the fifth edition of SN 5151 (March 2009), data and documentation from Wave 17 were added to the study. Also, updated data files for Wave 16 were deposited, because the values of derived variables relating to the start date of job spell in progress at the time of the interview had been recalculated, and imputations for Wave 16 which form part of cross-wave imputation schemes had been updated. Further details of changes are available in Volume A of the documentation
• For the sixth edition (May 2009), an updated version of the data file QINDRESP in Wave 17 was deposited. In the previous version, a problem had been identified, where for individuals who reported that they were still working in the same job as at the last wave, the occupation codes in the main job were corrupted, for both the 1990 Standard Occupation Classification variable (QJBSOC) and the 2000 Standard Occupation Classification variable (QJBSOC00). A range of derived classification variables were also affected. These were as follows: QJBSEG, QJBGOLD, QJBRGSC, QJBCSSM, QJBCSSF, QJBHGS, QJBSEC, QMRJSOC, QMRJSEG, QMRJGOLD, QMRJRGSC, QMRJCSSM, QMRJCSSF, QMRJHGS, QMRJSEC. The problem did not affect individuals in a new job or with a new occupational description (QJBCK1 > 1 or QJBSOCP=2 or QJBSOCP=-1). The problem has been rectified in the updated file.
• For the seventh edition (July 2010), data and documentation for Wave 18 have been added to the dataset. In addition, there have been some major changes and enhancements going back to wave 1, as described in Appendix 4 of Volume A of the documentation

  DATA PROCESSING NOTES

  
  Data Archive Processing Standards

  The data were processed to the UK Data Archive's A standard. A rigorous and comprehensive series of checks was carried out to ensure the quality of the data and documentation.�Firstly, checks were made that the number of cases and variables matched the depositor's records. Secondly, checks were made that all variables had variable labels and all nominal (categorical) variables had value labels. Where possible, either with reference to the documentation and/or in communication with the depositor, absent labels were created. Thirdly, logical checks were performed to ensure that nominal (categorical) variables had values within the range defined (either by value labels or in the depositor's documentation). Lastly, any data or documentation that breached confidentiality rules were altered or suppressed to preserve anonymity.

  All notable and/or outstanding problems discovered are detailed under the 'Data and documentation problems' heading below.
  
  Data and documentation problems

  Note that in a number of the files there are small numbers of variables with errant or unlabelled values.
  Variable 'LJHSIC' is not included in file 'ljobhist.sav'.
  Variable 'QNWSTAT' has been added to file 'qegoalt.sav'.
  Files '_hhsamp.sav' from waves 'i' to 'm' have a small number of missing cases as compared to previous edition. The same holds for files 'oindresp.sav' and 'qindresp.sav'. File 'pjobhist' has a number of additional cases, compared with previous edition.
  
  Useful Notes
  
  BHPS web pages:
  Users are advised to read the ISER BHPS web pages before beginning analysis.
  
  Documentation:
  Users should note that only the questionnaires and Volume A (Technical Report) are available in Adobe PDF format from the UKDA catalogue record and in the download zip files. The BHPS codebooks and questionnaire and survey documents are available online from the BHPS documentation web pages (follow links on pages for each wave).
  
  Data conversion information

  From January 2003 onwards, almost all data conversions have been performed using software developed by the UKDA. This enables standardisation of the conversion methods and ensures optimal data quality. In addition to its own data processing/conversion code, this software uses the SPSS and Stat/Transfer command processors to perform certain format translations. Although data conversion is automated, all data files are also subject to visual inspection by a UKDA data processing officer.

  With some format conversions data, and more especially internal metadata (i.e. variable labels, value labels, missing value definitions, data type information), will inevitably be lost or truncated owing to the differential limits of the proprietary formats.�A UKDA Data Dictionary file (in rich text format), corresponding to each data file, is usually provided for viewing and searching the internal metadata as it existed in the originating format. These files are called: [data file name]_UKDA_Data_Dictionary.rtf
  
  Important information about the data format supplied

  The links below provide important information about the format in which you have been supplied the data. Some of this information is specific to the ingest format of the data, that is the format in which the UKDA was supplied the data in. The ingest format for this study was SPSS
  
  Please click below to find out information about the format that you have been supplied the data in.
  
  

  SPSS (*.por)

  SPSS portable (*.por files)
  If SPSS portable was not the ingest format, this format will generally either have been created via the SPSS command processor (e.g. if the ingest format is SPSS .sav, SAS, Excel, or dBase), or if the ingest format was STATA, the SPSS version will be created via the Stat/Transfer command processor. If the ingest format was undelimited text, the data will have been read into SPSS using an SPSS command file.

  Issues: There is very seldom any loss of data or internal metadata when importing data files into SPSS. Any problems will have been listed above in the Data and Documentation Problems section of this file.

  STATA (*.dta)

  STATA (*.dta files)
  If STATA was not the ingest format, all STATA files will have been created from SPSS .sav format via the Stat/Transfer command processor. Importantly, Stat/Transfer's optimisation routine is run so that variables with SPSS write formats narrower than the data (e.g. numeric variables with 10 decimal places of data formatted to FX.2) are not rounded upon conversion to STATA because they are converted to 'doubles ' rather than floats. User missing values are copied across into STATA (as opposed to being collapsed into a single system missing code).

  Issues: There are a number of data and metadata handling mismatches between SPSS and STATA. Where any data or internal metadata has been lost or truncated, this will have been automatically logged in this file: 5151_SPSS_to_STATA_conversion.rtf Note that the complete internal metadata has been supplied�in the UKDA Data Dictionary file(s): [data file name]_UKDA_Data_Dictionary.rtf

  
  Tab-delimited text (*.tab)
  
  If tab-delimited text was not the ingest format, tab-delimited files�will have been�created from SPSS portable files via the SPSS command processor, and also from Excel and MS Access files. When exporting from Access data tables to tab-delimited text, the�potentially problematic�special characters (tabs, carriage returns, line feeds, etc.) allowed by Access memo and text fields� are stripped out by the UKDA.

  Issues: Date formats in SPSS are always exported to mm/dd/yyyy in tab-delimited text format - so�there be be a�mismatch with the documentation on such variables. Variables that include both date and time such as dd-mm-yyyy hh:mm:ss (e.g. 18-JUN-2001 13:28:00), will lose the time information and become mm/dd/yyyy. If the time information is critical, a new variable will have been created in the tab-delimited data file by the UKDA. All users of the data in tab-delimited format should consult the UKDA Data Dictionary file(s): [data file name]_UKDA_Data_Dictionary.rtf

  If the data was exported from MS Access, more limited 'data documenter' information is suppied�in the file(s): [data table name]_variableinformation.rtf These files may also contain SQL setup information.

  
  MS Excel (*.xls files)
  
  If MS Excel was not the ingest format, Excel files�will have�been�created via the SPSS command processor. The date and time issues noted under tab-delimited format�apply to SPSS to Excel conversion via the SPSS command processor.
  
  SAS (supplied as *.dat and *.sas)

  If SAS was not the ingest format, all SAS files will have been created from SPSS .sav format via the Stat/Transfer command processor. The data files are provided as a fixed-width text file (*.dat) and a SAS command file (*.sas), which when run will create a SAS dataset. This enables the user to recreate the SAS dataset and formats library in almost all versions of SAS and all operating systems.

  Issues: The main loss of information when converting from SPSS to SAS is user-missing value definitions. By editing the .sas file, the user can choose whether to collapse all user-missing values into system missing or preserve the�value and lose the user-missing definition. To achieve the latter�the following section of the .sas file should be removed before running it:

  /* User Missing Value Specifications */

  Note that the complete internal metadata has been supplied�in the UKDA Data Dictionary file(s): [data file name]_UKDA_Data_Dictionary.rtf

  
  MS Access (*.mdb files)

  Due to the substantial incompatibilities between versions of MS Access, the UKDA only make data available in MS Access format if this is the ingest format and the database contains important information in addition to the data tables (coding information, forms, queries, etc.).

  
  
  Conversion of documentation formats

  Electronic and paper documentation supplied with this study is usually incorporated into the UKDA User Guide (in PDF format). The conversion programmes used are the latest versions of Adobe PDF Writer for electronic documentation and Adobe Paper Capture (Acrobat 'plugin' version) for paper documentation. Occasionally, some�of the electronic documentation cannot be usefully converted to PDF (e.g. MS Excel files with wide worksheets) and this is supplied in�a more appropriate format. All User Guides are fully bookmarked.