Improving the use of self-generated identification codes.

In panel studies on sensitive topics, respondent-generated identification codes are often used to link records across surveys. However, usually a substantial number of cases are lost due to the codes. These losses may cause biased estimates. Using more components and linking the codes by the Levenshtein string distance function will reduce the losses. In a simulation study and two field experiments, the proposed procedure outperforms the methods previously applied.