Marriage formation as a process intermediary between migration and childbearing

In studies of differences in fertility between migrants and non-migrants, marriage interferes because migration can be motivated by an impending marriage or can entail entry into a marriage market with new opportunities. One would therefore expect elevated fertility after migration, although a competing theory states that on the contrary fertility ought to be reduced in the time around the move because migration temporarily disturbs the life of the migrant. In any case marriage appears as a process that is intermediary between migration and childbearing. To handle such issues it pays to have a technique that allows the analyst to separate any disruptive effects of migration from any boosting effects of marriage in studies of childbearing. The purposes of the present paper are (i) to remind us that such a technique is available, in fact is straightforward, and (ii) to apply the technique to further analyze a set of data on migration and first-time parenthood in Kyrgyzstan recently used by the second author and Gunnar Andersson. The technique has the neat feature that it allows us to operate with several “clocks” at the same time. In the analysis of first births we keep track of time since migration (for migrants) and time since marriage formation (for the married) beside the respondent’s age (for women at childbearing ages); in other connections there may be more clocks. For such analyses we make use of a flexible graphical housekeeping device that allows the analyst to keep track of a feature like whether migration occurs before or after marriage, or at the same time. This is a half-century-old flow chart of statuses and transitions and is not much more complex than the famous Lexis diagram, which originated with Gustav Zeuner, as we now know. These reflexions were first presented at a symposium dedicated to Professor Zeuner.