Usage of quota sampling in Czech migration surveys Results stability as an indicator of data quality Josef Bernard, Yana Leontiyeva Institute of Sociology AS CR

Questions and context QUESTIONS representativeness of quota samples of immigrant population? Stability of results among several surveys as an indicator of reliability Possible sources of bias? CONTEXT Quota sampling is the predominant sampling methodology in Czech migration surveys

Number of foreing citizens in the Czech Republic Note: * 2013 data is valid for 30 th of April ; for the rest of the years - 31 st of December Source: Czech Statistical Office, Directorate of Alien Police, Ministry of the Interior of the CR 2013 International Labour Migration in the Czech Republic: an Overview with a Special Focus on Over-qualification

Structure of non-EU Immigrant Population, October registered foreigners slowly decreasing 47% permanent residence permit rapidly growing Average length of residence increasing

Czech surveys targeting immigrants YearPopulationN Sampling strategyIncentivesInterview 2001 Employed non-EU Nationals923 Quota, based on official databaseno face to face, interviewer administered 2006 Employed non-EU Nationals1011 Quota, based on official databaseno face to face, interviewer administered 2010 Economicaly active non-EU Nationals1041 Quota, based on official databaseno face to face, partially self administered 2013 Ukrainian and Vietnamese nationals912 Quota, based on census 2011no face to face, self administered

Quota sampling as the dominant Czech sampling strategy Strengths Financially and organisationally relatively uncomplicated Use of existing interviewer networks possible Coverage of the whole country Weaknesses representativeness of the sample questionable – expected bias towards more integrated respondents with better knowledge of Czech language Limited language competencies of interviewers Limited control over the process of respondent search and the interview process – quality of interviewer network crucial Quotas not accounting for unregistered immigrants

Strategies used for minimalisation of risks Use of stable and time-proven inteviewer networks Self administered questionnaires in foreign languages (2010, 2013) Interviewers equipped with a letter of invitation to participate in the survey in foreign language (2010, 2013) Interviewers equipped with regional database of places with concentration of foreigners (2010, 2013) Adding ad hoc recruited ethnic interviewers in regions with the highest concentration of foreigners (2010)

Stability of results as an indicator of data quality Stability of results indicates reliability of the data (Systematic biases doesn’t have to result in data unstability). Comparison of results stability in all 4 surveys Common subgroup in all data sets – employed Ukrainians with long-term residence permit, residing more than 1 year in CR Variables to be compared Length of stay in CR Occupation (ISCO) Education Marital status Locality of living Relationship between variables Ukrainian a Vietnamese economically active immigrants (2010, 2013)  Gender x Education  Gender and experience with transnationality of the family

Analysis of results stability Length of stay Stable, in 2013 increase of long-term stays and decrease of short term stays Occupation Gradual increase in employment in the service sector Unstable share of unqualified workers Education Stable, in 2013 increase of more educated immigrants Marital status Stable Locality of living 2001 less concentrated to Prague

Stability of variable relationships Gender x Education Significant better education of Ukrainian women No difference in Vietnamese population Relationship stable 2010 and 2013 Gender and transnational families Significant more Ukrainian men living separated from the family No difference in Vietnamese population (very low incidence) Relationship stable 2010 and 2013

Hypothetical reasons of unexplained unstability Occupational structure Coding of open questions – difference between qualified and unqualified occupation often difficult to asses Residential concentration Unsuitable spatial distribution of interviewer networks

Lessons learned about quota sampling Prevailing stable results and expectable trends Missing incentives are not a crucial problem of data collection Limited possibility of interviewer control leads in some cases to suspect questionnaires Additional interviewers need in some cases to be added in stable interviewer networks Self administered questionnaires are partly a solution of the problem of representativeness and sensitivity, but worsen the problem of limited control over the interview process

THANK YOU FOR YOUR ATTENTION Josef Bernard, Yana Leontiyeva Institute of Sociology AS CR