The surge in international migration over the past half century has forced all developed countries to reassess the rules by which immigrants can make the transition to citizenship. In this same period, the importance of citizenship has grown. Increasingly, it entails not simply a legal transition for immigrants but also a new set of entitlements and civic responsibilities that creates pressures for immigrant-receiving states as well as for native populations in these countries, often native populations whose numbers are in decline.

This surge in international migration and the need to incorporate ever larger numbers of immigrants also offers a challenge for scholars. While the determinants of international migration have long been theorized and tested, the formal and informal incorporation of immigrants into their countries of migration has been undertheorized and, in many cases, simply assumed to follow immigration. Thomas Janoski and Marc Morjé Howard each seizes the analytical opportunities presented by simultaneous pressures to restructure citizenship policies in the developed world in order to develop and test models for policy change and for formal immigrant incorporation through citizenship policies and naturalization.

In The Politics of Citizenship in Europe, Howard analyzes the historical development of citizenship policies across Europe to assess why some countries have developed more liberal policies than others and why policies have changed in some of the countries that traditionally had restrictive policies in recent years (roughly the 1990s and early 2000s) but not in others. National citizenship policies are measured through a Citizenship Policy Index (CPI) that includes three components: jus soli for the children of immigrants born in the country of migration, naturalization requirements, and the tolerance of dual citizenship. Each component is measured on a scale of zero to two, with a total possible CPI of six for the most inclusive country. Through a series of case studies of the 15 older European Union states, Howard develops a typology of countries that have traditionally had restrictive policies and have maintained these policies, countries that have steadily liberalized restrictive policies, and countries that have had historically liberal citizenship policies. Restrictive continuity appears in Austria, Denmark, Spain, Italy, and Greece. Liberalizing change has appeared in Sweden, Finland, Luxembourg, the Netherlands, and Portugal. Countries with historically liberal policies include France, Belgium, the United Kingdom, and Ireland. Germany's experience does not fit so clearly into the author's typology. There, the effects of a partial liberalization have been limited by a restrictive backlash.

What explains these different outcomes? Howard offers a two-part explanation. First, states that engaged in significant levels of colonialism ultimately developed more inclusive policies. The irony of this is not lost on Howard, who offers a thoughtful critique of how the historical mission of transforming colonial subjects evolved into a more expansive notion of national identity and tolerance of ethnic blending in the contemporary era. Second, he argues that the early adoption of democratic norms in the nineteenth century, with concomitant development of an inclusive norm of civic engagement, increases the likelihood of more inclusive citizenship policies.

In The Ironies of Citizenship, Janoski models naturalization rates in 18 advanced democracies (Western European immigrant-receiving countries plus Japan, Canada, New Zealand, Australia, and the United States) from 1970 to 2006. He also offers detailed, historically grounded case studies of nationality policies in these countries. Like Howard's, Janoski's model theorizes a positive effect on naturalization rates of having been a colonial power, contrasted in his model with being a short-term occupier or a settler regime in which opportunities for international migration resulted from the forced decline of the indigenous population. The model also includes political, demographic, and economic control variables. The political variables include relative left- and green-party representation in the legislature and women members of parliament. The demographic controls focus on migration rates and the economic controls include unemployment rates and GNP per capita. In very simplified form, he finds that regime history matters and that the substantive effect on naturalization rates is high. The level of left- or green-party representation in the parliament also increases naturalization rates. Economic and demographic factors proved less important in shaping naturalization outcomes.

For Janoski, then, the “irony” of citizenship is that countries that colonized others and decimated indigenous populations as part of their colonial rule are as open today to incorporating immigrants as are the settler countries that have long relied on immigrants to build their numbers and economic strength. For this process to lead to more incorporative policies in the contemporary era, the period of colonization must be long (Janoski estimates at least 50 years). A second, though less completely developed, irony of citizenship is that settler countries had to eliminate or subjugate indigenous populations as part of the process of national development that spurred migration and, ultimately, naturalization of migrants from Europe and other parts of the world.

Each of these books advances the scholarship on immigrant incorporation in advanced democracies considerably. Janoski and Howard move the study of citizenship among immigrant communities from the shadows of the immigration scholarship to its own field. Janoski has a slight advantage in that The Ironies of Citizenship was published somewhat after Howard and makes some passing references to The Politics of Citizenship in Europe.

To a significant degree, each volume neglects the question of immigrant organization and immigrant agency. The decision to naturalize is far from automatic for many immigrants, and the administrative barriers and costs can be high. So, one question that needs to be asked is how these regime types and the structural conditions in each of the countries under study encourage immigrants to pursue citizenship. This is not simply a question of immigrant agency. Countries that provide benefits and rights to immigrants comparable to those of naturalized citizens, for example, may well reduce the incentive to naturalize. That said, naturalization rates result from the decisions of immigrants and immigrant communities about where their ultimate political loyalties lie. Nations with a richer infrastructure of immigrant civil society organizations are likely to see higher naturalization rates. Although Janoski finds that the presence of left- and green-party parliamentarians increases naturalization rates, recent naturalization patterns in the United States show that an active anti-immigrant movement in the society can spur higher naturalization rates, particularly when immigrants come to see themselves as stigmatized by the larger society. Thus, the immigrant position in each of these countries and the resources immigrants have to respond to societal pressures need more attention.

A smaller concern arises in Howard's study. One of the three components of the CPI is tolerance of dual citizenship. At a theoretical level, it is not so clear that this component should be of equal value to the other two. Jus soli and naturalization are arguably more central to immigrant incorporation than is tolerance of dual citizenship and should have higher weight in the CPI. My assessment would be that dual citizenship is the outcome of successful immigrant incorporation; once settled and naturalized, immigrants can use their new position to advocate for greater tolerance of dual citizenship. I am also concerned that tolerance of dual citizenship is somewhat more difficult to measure than Howard indicates. While many countries have policies that prohibit dual citizenship, the practice on the ground in often considerably different and often offers idiosyncratic exceptions for some nationalities.

Despite these concerns, each of these volumes is a necessary and welcome read to better understand the process of immigrant political incorporation in advanced democracies. They set a high bar for the next generation of studies of immigrant political incorporation that analyze indicators other than naturalization and nationality.