Are there duplicates in the Aadhaar database?

A data point that has gained attention from our recently released State of Aadhaar Report 2017-18 is the number and percentage of duplicate Aadhaar letters.

Here is a screenshot of the relevant page and footnote from our report.

The percentage of respondents who possessed more than one Aadhaar letter with a different Aadhaar number was 0.1 percent. As we reported, this number can be an underestimate because individuals who intentionally have two Aadhaars will have an incentive to not openly report this.

The 0.1 percent figure (calculated using sample weights) represents three cases of duplicates in our sample of 2947 respondents. In the table below, we provide some basic information about the three individuals that have duplicate Aadhaars.

Three insights emerge from this table:

  1. All three Aadhaars were issued in the early years of enrolment. This may imply that earlier Aadhaars had higher data quality or process related issues.
  2. All three Aadhaars are from Andhra Pradesh. This may imply the issue is more isolated to Andhra Pradesh. We extrapolate this figure, however, to the all-three state level including Rajasthan and West Bengal. However, we do not have sufficient data to be sure whether this problem exists in these two states as well.
  3. There is no systematic pattern of duplication with respect to age, gender, and location. With just three cases, it is difficult to comment on trends but there appears to be no clear trend in terms of age, gender or location.

While our teams were able to verify that there were indeed two Aadhaars for the same person, this does not mean that both exist digitally as well. If so, one of the Aadhaars cannot be used for digital authentication, but can still be used in its analog form.

Given the high usage of Aadhaar in its analog form (more than 93% across all three states in our survey), the prevalence of duplicate Aadhaar letters poses a significant risk of fraud. This reinforces the need for better security features on the Aadhaar letter.

We hope our report and blog post facilitate meaningful dialogue on this subject and we welcome any questions and suggestions you may have.