Can I merge basic monthly data with March supplement?

Hi Rasoul,

You’re essentially dealing with two problems:

  1. Merging the “March Supplement” (the ASEC) with the March basic/monthly

  2. Merging the March basic with the April basic

Regarding problem #1, it’s a notoriously tricky problem. MPC researchers Jose Pacas & Sarah Flood are working on it, and from 1989 onward, you can follow their algorithm described here. A number of people (such as this thread and this thread) have asked when this variable will be available in the standard IPUMS release, but as of yet, there seems to be no word.

Regarding problem #2, it depends on which years you’re using since the specific set of variables you need for cross-month merging changes over time. You should have a look at some of the references in Pacas & Flood, particularly Drew, Flood, and Warren (2014). They discuss this issue in depth. But IPUMS has created a variable to do this merging (CPSIDP).

As a general comment, your variable names make it clear that you’re not using IPUMS data. Usually, MPC researchers don’t respond to general CPS questions, particularly because different data providers use different variables and it’s impossible to keep track of them all. I suggest using IPUMS, or figuring out a way to ask your question in terms of IPUMS variables.

Hope this helps,

Mitch