Immigration has recently been at the centre of the political and economic agenda. Economists have studied extensively the impact of immigration on several economic and social indicators of host countries. The effect of immigration on innovation and technical change is, however, not much studied. The existing work on the effect of immigrants on innovation is generally limited to the role played by highly educated immigrants, generally immigrants with at least tertiary education, and is mostly focused on the US. Yet, although in anglosaxon countries skilled immigration is a sizeable phenomenon -- according to the Docquier and Marfouk (2006) data the percentages of tertiary educated immigrants were in 2001 40.3% for Australia, 58.8% for Canada, 34.9% for the UK, ad 42.7% for the US -- this is much less the case in European countries, for which just the minority of immigrants are skilled. Just to take a few figures, according to the same source, the percentages of tertiary-educated immigrants were 16.4% for France, 21.8% for Germany, 15.4% for Italy and 18.5% for Spain. Now, although the existing literature has emphasized why there are good reasons to expect positive effects of skilled immigrants on the innovation of the receiving countries, it has much less to say about the general effect of immigrants, or of low-educated immigrants. In this paper, we make an attempt to partly fill the gap concerning the effects of overall immigration on innovation, and in particular of low-skilled immigrants, existing in the literature. In addition to providing evidence for a country which was exposed to a very fast and large wave of immigration during the 2000s -- Italy --, and for which evidence is scant, we also use a very small geographical scale of analysis -- Italian provinces corresponding to NUTS-3 regions --, which presumably enables us to better control for differences in institutional and socio-economic factors which are difficult to observe but which may simultaneously contribute to both attracting new immigrants and to increasing the innovation potential of a region. More importantly, unlike most papers in the literature which only investigated the effect of skilled immigration, (i) we first focus on the general impact of immigration on innovation, and then (ii) separately look at the effects of low-educated and high-educated immigrants on innovation. Last but not least, we tackle potential endogeneity issues by using a well established instrumental variables (IVs, hereafter) strategy based on immigrants' enclaves.
