Pnina ZADKA Central Bureau of Statistics Israel Record Linkage and Preference Procedures in an Integrated Register Based Census Pnina ZADKA Central Bureau of Statistics Israel 01 אוקטובר 19 Pnina ZADKA, ISRAEL

Content of Presentation Data sources Auditing data sources Record linkage Data sources preference procedure 29 May 2007 Pnina ZADKA, ISRAEL

Administrative Data Sources National Population Register (NPR) National Insurance Institute (Social security and National Health Insurance) Income taxes Municipal welfare Border Control Telephone numbers School enrolment 29 May 2007 Pnina ZADKA, ISRAEL

Auditing Administrative files Identifying potential biases Validity Completeness 29 May 2007 Pnina ZADKA, ISRAEL

Administrative Potential Biases Administrative biases in address Taxes (peripheral localities) School enrolment (region preferences) Student (scholarships eligibility) Workplace Data entry mistakes Sources with known biases in address were used only if the address was consistent for all administrative family members 29 May 2007 Pnina ZADKA, ISRAEL

Administrative Potential Biases Administrative population omissions Non residents ( students, workers, displaced) Avoiding contact with official authorities (felons) Eligible/not eligible for the service Adding persons from complementary sources with duplication checks by: inclusion specification, names and ID using deterministic/probability record linkage 29 May 2007 Pnina ZADKA, ISRAEL

Validity Checks Validity of ID number Verification of legitimacy of control digit (based on the formula in use) Existence of the number in the NPR Only records passing the validity checks were considered for updates or adding information not included in the NPR 29 May 2007 Pnina ZADKA, ISRAEL

Matching files Hierarchy Updating for populations NPR Border control + Births and deaths Social Security Updating address Electricity meters School enrolment Vehicle registrations 29 May 2007 Pnina ZADKA, ISRAEL

Creating Administrative Families NPR - all family relations Residing in the same NPR address Adding optional address Matching of single persons Family reconstruction – iterative procedure (approximately 3 iterations) 29 May 2007 Pnina ZADKA, ISRAEL

Record Linkage Full compatibility with NPR (deterministic procedure) ID number including control digit Given name, sex, date of birth Records were matched if all were identical and a comprehensive record was formed including information from all matched files. 29 May 2007 Pnina ZADKA, ISRAEL

Record Linkage Probabilistic procedure Name (sure and given) with spelling errors and vowels omissions. sex Year of birth Weighted Hierarchy of variables. Threshold of probability matched correctly, exceeding 85% (probability computed from pilot censuses and previous traditional censuses) Address was not used for matching - a core variable to be updated! 29 May 2007 Pnina ZADKA, ISRAEL

Conclusions Administrative sources are important and affordable data sources Data sources should be examined for inherent flaws Hierarchy of validity should be established Use of converging iterative procedures Verification of process with traditional enumeration methods 29 May 2007 Pnina ZADKA, ISRAEL