What determines which censuses are included in IPUMS?

Dear IPUMS staff and users,

I am using IPUMS international data for several African countries. Two very basic questions in this regard

  1. What determines which censuses IPUMS has samples available from?

For instance, why are countries such as Botswana and Namibia not included? Or, more systematically, compared to a “full” list of censuses, e.g. here:


Is this a matter of the national statistical agencies being unwilling to publish the data or a matter of finite time and manpower at IPUMS? If the latter, what determines which countries you are including in your updates?

To be sure, this is not intented in any way as a critique - the data you make freely available are incredible. I just would like to get a better sense of what determines selection.

  1. Related to the first point, which countries do you plan to release in the immediate future? The website lists these dates


In the forum, I found this:

Which of those is accurate?

Many thanks in advance for your help – and apologies if I overlooked answers to these questions in the forum.

The full series of census samples for Botswana is in the 2016 release. Unfortunately the entire 2016 release has been postponed from June to September, then December and now may be postponed again. Many intricate details must be checked, verified, and re-checked before a release of a couple dozen samples totalling 50-100 million person records is given the green light.

First, for a country’s microdata to be integrated into IPUMS-International, the statistical agency must endorse a uniform memorandum of understanding agreeing to the general principles of access by users. Statistics Botswana signed the MOU Feb. 20, 2008. For Nambia, the document was signed in late 2014. More than 100 NSOs have signed, but that leaves another 60 with a population of 1/2 million or more that have not, now 17 years into the project. Fortunately, last April, the UN Population Commission issued a resolution urging census agencies to make microdata accessible and citing IPUMS-International for good practices. So far, in response, only one NSO has since signed the MOU, but we are hopeful that more will in the next year or 3. Please see our partners page for a list of cooperating NSOs.

Second, the microdata must be entrusted. The series of census microdata of Botswana was entrusted Dec. 12, 2014, too late for the 2015 release so it was scheduled for 2016. the Namibia series was entrusted in late 2015, but we have discovered some issues in linking person records to households and dwellings for the 2001 and 1991 censuses. Once those issues are resolved the series will be scheduled for release.

Third, once the MOU is signed and the microdata are entrusted and verified, salience, timeliness and user interest are the principal considerations, taking into account that not all microdata entrusted can be processed at once. A series with a 2010 round census for a large country where microdata are difficult to access is rushed through as quickly as possible, while a small country where no census has been taken in decades, and few users have expressed interest in accessing the microdata receives a low ranking.

Expressesions of interest and support by researchers are exceedingly helpful in persuading NSOs to cooperate. For example, if Indian researchers, universities, and institutions do not mobilize to pressure the Registrar General, the Indian census microdata will not accessible to researchers. Likewise, the ONS-UK, has delayed entrusting a sample for the 2011 census in part because British researchers have not visibly manifested their disappointment. User assistance is greatly appreciated. Thank you for your expression of interest.