PPD Frequently Asked Questions

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How to . . .

Wait, how can I download the data again?

First, click on this link. Scroll down past the description until you see a list of files. The dataset is a .zip file, the latest version will be…

I imported the ppd_summary.csv file, but the data seem wrong. How can I interpret these data?

The issue here is that the ppd_summary.csv file is saved using RFC 4180 csv conventions, that is, with a dot marking the decimal and a comma…

How can I merge my other data into the PPD using ISO or other country codes?

First, add whatever country codes are needed to the PPD data: there are routines for both Stata (kountry; type findit kountry in Stata’s command…

The PPD Data

What about Russia and the rest of the former Soviet Union? Yugoslavia? Czechoslovakia? Pakistan? Sudan? Ethiopia? Why are there estimates for successor states before they actually existed?

For countries that have undergone partition, the PPD estimates for a given year include all of the origin country’s then-current territories. This…

The estimates for Ruritania, among others, have changed since the previous version. Why is that?

There are two reasons why estimates change from one version of the PPD to the next. The first reason is that we have incorporated new source survey…

How is Germany treated in the PPD? Where’s East Germany?

Germany is West Germany only before 1991 and (united) Germany from that point forward. The PPD includes no estimates for East Germany; we just…