Exodus: How Migration Is Changing Our World

Collier once more addresses The Role of Integration and Assimilation in Multicultural Societies. He sees modern nationalism as necessary for social cohesion, economic redistribution, and a shared sense of identity, pushing back against the rise of individualism and globalism. He questions the idea that people act primarily out of self-interest and draws on research by Michael Sandel, Jonathan Haidt, and Steven Pinker to support the importance of social bonds. Sandel argues that shifting essential goods from communal provision to private transactions weakens social responsibility. Haidt’s research suggests that people are naturally inclined to cooperate and that national identity builds trust. Pinker connects empathy and declining violence to a sense of shared identity, linking it to cooperation and social stability. Collier brings these perspectives together to argue that nationalism, when managed responsibly, helps maintain a functioning and unified society.

Collier uses Catalonia’s secessionist movement as a case study to demonstrate how a weakening sense of national identity undermines economic redistribution. Catalonia, Spain’s richest region, has long contributed a significant portion of its wealth to the Spanish government, which then distributes funds to poorer regions such as Extremadura and Andalusia. However, as Catalan nationalism has grown stronger, support for this redistribution has diminished. Many Catalans now view these transfers not as a collective responsibility within a shared national community, but as an unfair burden imposed by an external state. Collier argues that this shift illustrates a broader trend: When national identity weakens, wealthier regions become more reluctant to subsidize poorer areas, seeing themselves as separate entities rather than part of a unified whole.

He contrasts this with the European Union, where redistributive mechanisms are significantly weaker despite decades of political and economic integration. While national governments collect and redistribute large portions of GDP to ensure regional equity, the EU’s budget redistributes only a tiny fraction of European income. The reluctance of wealthier EU nations, such as Germany and the Netherlands, to fund struggling economies like Greece and Italy during financial crises highlights the limitations of supranational institutions in fostering economic solidarity. Collier attributes this reluctance to the lack of a strong European identity; whereas citizens of nation-states feel a shared obligation to their fellow nationals, Europeans do not see themselves as part of a singular political community in the same way.

Through these case studies, Collier reinforces his argument that the nation-state remains the most effective unit for economic cooperation and redistribution. National identity fosters mutual regard among citizens, making them more willing to support policies that benefit the collective good rather than just their immediate communities. Without this sense of shared belonging, redistributive policies face increasing resistance, leading to greater economic disparity and political fragmentation. Collier suggests that efforts to weaken national identity—whether through regional separatism or the erosion of nation-states in favor of global institutions—risk undermining the very mechanisms that sustain economic equity.

Multiculturalism, in Collier’s view, further complicates national cohesion. He critiques policies that promote cultural separation, arguing that they weaken trust and create fragmented societies. He contrasts separation with assimilation and fusion models, historically successful in reinforcing national unity. However, modern migration patterns make assimilation more difficult, requiring policies that encourage integration through language learning, geographic dispersion, and shared civic identity. Without such measures, he warns, societies risk becoming “postnational,” where national identity is reduced to a legal status rather than serving as a unifying force.

Collier ends the book with these chapters because they reinforce his main argument: Strong national identity is essential for economic stability and social cohesion. He has spent the book critiquing both extreme nationalism and unrestricted migration, arguing that nations must carefully manage migration while maintaining a sense of shared identity. He warns that without clear migration policies, societies risk becoming fragmented, making redistribution and trust more difficult.

Collier frames the book with a personal narrative, opening with his grandfather’s migration and closing with his father’s decision to assimilate, invoking The Power of Narratives in Migration Policy. His grandfather represents the typical migrant seeking economic opportunity. By the end, Collier shifts focus to his father, who chose full integration—changing his last name and embracing a new national identity. Collier argues that such a decision, not migration alone, determines long-term social cohesion. His personal anecdotes thus illustrate his argument that successful migration depends on integration, not just movement from one country to another.