How integrated are immigrants

1. IntroductionImmigrant integration is a political priority. Both OECD and the European Union have declared that its achievement plays a key role in future growth, social cohesion and wellbeing (European Commission 2010; OECD 2014). At the same time, we witness frequent mass-media coverage of integration-related problems and a global surge in outspoken anti-immigration political parties. This mismatch between objectives and reality in terms of integration is not unique to our time (Casteles and Miller 2009). Despite the enduring nature of integration problems and their political relevance, simple but paramount questions regarding the integration process remain unanswered. Examples of such questions are: How integrated are a country's immigrants? How does the integration process respond to a rise in immigration? Which mechanisms drive the process? Here we argue that attending to these questions scientifically bring to the surface important information about how to cope with integration challenges more effectively. To this end, we illustrate a method which, using register data, extracts precise quantitative answers to this type of question. We look at two integration contexts - labour market integration and social integration. The lesson that the data teach us is that the former is an integration process with the intrinsic ability to absorb an increase of immigration, while the latter is not. Data and theoretical analysis also suggest that these differences are due primarily to the social network effects governing social integration, and which are found absent in formal labour market integration. When social network effects are present, the progress of integration is seriously delayed as immigration rises. Hence, policy makers wanting to promote global integration effectively must cope with two opposed processes operating at significantly different speeds.2. Quantifying integration and defining full integrationTo answer the simple questions on integration performance and progress, we opt for a systemic approach to integration. A systemic approach is methodologically different from traditional integration studies. The latter are primarily preoccupied with explaining the multiple causes operating on individual integration outcomes, and predominantly engaged with time series analysis.3 A systemic approach operates at a different analytical level. An example of a systemic approach would be to assess the functional dependency of an integration quantifier such as, for example, local intermarriage rates, on a variable describing an important characteristic of the system, such as, for example, local immigrant density. Furthermore, the functional dependency is assessed regardless of space and time coordinates or any individual or contextual characteristics. In what follows we show that, while losing the details of the micro level structure, a systemic approach, using significantly fewer variables than traditional accounts, effectively benchmarks integration processes. We also show that this approach can uncover the underlying nature of different integration processes in a society.To answer the question of how integrated immigrants are we first have to define integration, and more importantly, when an immigrant population is fully integrated. Take the fraction of inter-marriages in a municipality. An immigrant minority population is completely segregated from the native majority population if the fraction of inter-marriages is zero in the municipality under study. With a systemic approach, it is easy to define a fully integrated immigrant population with respect to a given quantifier. This notion follows from the concept of indistinguishability. When the fraction of immigrants is γ (gamma), a simple computation shows that if immigrants and natives are indistinguishable the fraction of inter-marriages in a large population is 2γ (1 - γ ). To understand the meaning of full integration between two groups beyond its mathematical expression, an ideal experiment example can be useful. …