Comparability
Some early samples include less detail, providing dichotomous responses based on whether the interviewer observed IUDs in-stock (see the Codes tab to identify samples following this practice). In these early samples, if IUDs were not observed, they were assumed to be "out of stock". In later surveys, interviewers had the option of reporting that IUDs were "in-stock but not observed".
To maximize comparability with the earliest surveys, users should combine responses for "in-stock but not observed" with "out of stock," following the logic that only observed stock was initially treated as present. If users are working only with later sample rounds that include all three possible response categories, they may use all detail or combine codes 1 and 2 for all in-stock cases.
