Overcoverage is the result of the addition to the database of records excluded from the target population. If, for any reason, an immigrant record was not included in the Immigrant Landing File (ILF), it would not be part of the IMDB. Immigrants who do not file taxes for a given year or who file late would not have an IMDB_T1FF record although linked to tax and part of the population of interest. Undercoverage in the IMDB is in part the result of the exclusion of tax files of immigrant taxfilers from the database. These errors often result in undercoverage. They can create biased estimates, and the impact can vary for different sub-groups of the population. Coverage errors can result from inadequate coverage of the population. 7.1.3 Coverage errorsĬoverage errors are the result of omissions, erroneous additions, duplicates, and errors of classification of records in the database. See sections 7.2 and section 7.5 for some counts. For example, when a person has a record on both the ILF and the NRF, and the sociodemographic variables have inconsistent values, the values at admission (in the ILF) are kept. This type of error was taken into account in the creation of the Integrated Permanent and Non-permanent Resident File (PNRF) to avoid conflicting information for any individual. This type of error can be attributed to a number of factors, including data capture (e.g., typos) and respondent error (e.g., misinterpretation of the question asked). Measurement error is the difference between a variable’s measured value and its true value. It is possible that, in a few instances, some SIN connections are missed or false connections are made. The SDLE (described in Sections 2.3) allows for identification of these SINs. Both SINs are required in order to have a complete fiscal history from arrival in Canada. It is possible to miss part of an immigrant’s fiscal history since some immigrants have more than one social insurance number (SIN) through time (a temporary SIN assigned at arrival to the individual as a non-permanent resident, and later a permanent SIN assigned after admission). A link is considered a false negative when two records belonging to the same person are deemed a non-match. A link is considered a false positive when two records not belonging to the same person are deemed a match. Two types of errors are possible-false positives (false matches) and false negatives (false non-matches).
7.1.1 Record linkage errorsĭatasets produced from the results of record linkages are subject to record linkage errors.
However, the linkage itself presents a form of sampling error when links are missed. No adjustments are made for the missing tax years of filers or for linkage errors no sampling is performed and every linked taxfilers is kept in the final dataset. It is to be noted that, given that it is a census of immigrant taxfilers who were admitted in 1980 or thereafter, no weights are created in the IMDB. In this section, the sources of errors are explained and the prevalence of some of these errors is presented.
0 kommentar(er)
