Record Linkage and Preference Procedures in an Integrated Register Based Census

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

2. Content of Presentation Data sources Auditing data sources Record linkage Data sources preference procedure Pnina ZADKA, ISRAEL

3. 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 Pnina ZADKA, ISRAEL

4. Auditing Administrative files • Identifying potential biases • Validity • Completeness Pnina ZADKA, ISRAEL

5. 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 Pnina ZADKA, ISRAEL

6. 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 Pnina ZADKA, ISRAEL

7. 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 Pnina ZADKA, ISRAEL

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

9. CreatingAdministrative 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) Pnina ZADKA, ISRAEL

10. 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 identicaland a comprehensive record was formed including information from all matched files. Pnina ZADKA, ISRAEL

11. 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! Pnina ZADKA, ISRAEL

12. 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 Pnina ZADKA, ISRAEL