I study whether internal migrants assimilate culturally to the locals. Investigating
this question with observational data has been challenging because it requires
disentangling assimilation from sorting and because data on immigrants before
migrating is typically not available. I overcome this challenge by studying the
Swiss context, which provides an ideal setting for two reasons. First, as a result
of its history, Switzerland presents substantial cultural differences between its regions.
Second, the Swiss Household Panel tracks individuals for a long period
before and after they move. I exploit these two features to compare early and
late migrants in a difference-in-difference framework. I focus specifically on trust
in strangers, one of the most important components of culture and which has
been shown to predict growth and other desirable economic, social and political
outcomes. I find a statistically and economically significant evidence on assimilation
of migrants moving to higher and lower trust cantons, and this assimilation
happens in the first few years. Finally, using the Sorted Effects Method, I find
that assimilation is driven by the youngest immigrants, which is in line with the
impressionable years hypothesis in psychology.