Errors in Factual Questions and their Consequences Annette Scherpenzeel QMSS Seminar Lugano

Swiss Household Panel Aim Study of social change, in particular, the dynamics of living conditions in the population of Switzerland Method The survey "Living in Switzerland" is carried out among a sample of households representative of the Swiss resident population of Themes Computer-assisted telephone interviews are conducted with every person older than 14 in the households. Period Both objective data (resources, living conditions, life events, social position, participation, etc.) and subjective data (attitudes, perceptions, satisfaction, values, lifestyles, etc.) are collected Participation Since 1999, five waves have been carried out. The sixth will start in September 2004 Fieldwork In the first wave, 7799 persons in 5074 households have been interviewed. In the fifth wave, 5226 persons in 3296 households have been interviewed. Finance and organization The telephone interviews are conducted every year by the Institute M.I.S. Trend in Lausanne and Bern in German, French and Italian. The household-level interview takes on average 12 minutes, the individual interviews on average 55 minutes.

International Standard Classification of Occupations (ISCO) 1.Legislators, senior officials, and managers 2.Professionals 3.Technicians and associate professionals 4.Clerks 5.Service workers and shop and market sales workers 6.Skilled agricultural and fishery workers 7.Craft and related trades workers 8.Plant and machine operators and assemblers 9.Elementary occupations 10.Armed forces

ISCO Example 1 [1] Example taken from Bergman and Joye, "Comparing Social Stratification Schemas". Nuclear physicist unit group 2111 (physicists and astronomers) minor group 211 (physicists, chemists and related professions) sub-major group 21 (physical, mathematical and engineering science professionals) group 2 (professionals)

Elementary occupations Plant and machine operator assemblers Craft and related trades workers Skilled agricultural and fishery workers Service workers, market sales workers Clerks Technicians and ass- ociate professionals Professionals Legislators, senior officials, managers International Standard Classification of Occupations Distributions of first four waves

International Standard Classification of Occupations Change between first and second wave 4 % n = 4993 in 1999, n = 4673 in 2000 Year of panel data collection Percentage % 3 % 1 % 6 % 15 % 4 % Elementary occupations Plant and machine operator assemblers Craft and related trades workers Skilled agricultural and fishery workers Service workers, market sales workers Clerks Technicians and ass- ociate professionals Professionals Legislators, senior officials, managers

Variable ALL working persons Persons who have NOT changed job or employer Persons who have changed job or employer %% Type of employment: Self-employed, partner, private, employee Company: Number of employees (9 response categories) Percentage of part-time work (recoded into categories) Type of working hours: fixed, flexible, rotating Qualifications for job: Not sufficient, correspond, superior, not related Position: Management, training, production 68 Job tasks: Design, consulting, analysis Job with supervisory tasks: Yes, no Job with participation in decision making: Decision, opinion, no International standard classification of occupation (ISCO) Wright Goldthorpe Swiss Socio-Professional Categories (CSP-CH) Camsis n* * Total number of working persons with completed individual interviews in both 1999 and For some variables in the table the n was smaller because of filters to the questions (e.g. "Percentage of part-time work" was only asked to people working part-time).

Stability of various other demographic variables Percentage of people with the same score in 1999 and 2000 * Total number of persons with completed individual interviews in both 1999 and For some variables in the table the n was smaller because of filters to the questions ** Total number of working persons with completed individual interviews in both 1999 and For some variables in the table the n was smaller because of filters to the questions. VariableAll persons % Highest level of education achieved: 10 categories95 Actual occupation: Paid work, school, family, retired, unemployed, etc., 10 categories 94 Member of which political party: 16 categories90 From work module: Job limitation in time, Yes, no92 Part-time or Full-time92 Private company or government organization91 n10112* / 3828**

Four-wave Simplex model of ISCO Category 5 (Service workers, market sales workers) e3 e4 T2 ISCO catg 5 isc25 e T3 ISCO catg 5 isc T4 ISCO catg 5 isc T1 ISCO catg 5 isc15 e d1 d2 d3

Four-wave Simplex model using one indicator of hierarchy of work-position. T2 manage p00w34 e T3 manage p01w34 e T4 manage p02w34 e T1 manage p99w34 e d1 d2 d3

Coefficients estimated with the four-wave Simplex model for all ISCO categories. n in 1999* Reliability coefficient Stability coefficient ISCO (dummy variables)T2T1T3T2T4T3 1 Legislators, senior officials, managers Professionals Technicians and assoc. professionals Clerks Service workers, market sales workers Skilled agriculture and fishery workers Craft and related trades workers Plant and machine operator assemblers Elementary occupations n total**2370 * Frequency distribution of ISCO-1999 for persons having a valid ISCO score in all four waves. ** Total number of persons who have a valid ISCO score in all four waves.

General two-wave causal model of satisfaction condition 1 in wave 1 condition 1 in wave 2 condition 2 in wave 1 condition 2 in wave 2 condition 3 in wave 1 condition 3 in wave 2 satisfaction in wave 1 satisfaction in wave 2 relative situation event between waves Stable Component

Contribution of the different factors to the explanation of satisfaction DOMAIN relationsworkhealthfinances Percentage of explained variance FACTOR Stable component Relative situation Events Living conditions

Conclusions Repeated cross-sections give a false impression of stability in "objective" variables. In reality, these variables can contain considerable random variation This unreliability can only be known by repeating the same question in each wave. Because of the nature of the "objective" variables, we can distinguish unreliability from real change The unreliability in the "objective" variables affects their explicative power in longitudinal models. It impairs the opportunities to analyze labor market mobility by panel studies

Discussion: What is the cause Swiss Household Survey data collection Not likely: many other variables are stable ISCO coding database SOEP-EG: 20% no change in occupational title but change in occupational class. But: other working variables also unstable? Interviewer: interpretation, training, search strategy, etc Explains only about 2% of the variation over waves Time-interval between measurements: missing events? Selection bias: attrition nor occupational mobility are randomly sampled But: this would select for stability overestimation? Respondent: interpretation, frame of reference, memory, satisfice, etc Question formulation

Next: ISCO: Compare with retrospective data from the same respondents ISCO: Compare ISCO occupational title with occupational class Other variables: methodological experiment?