Naturalization proclivities, ethnicity and integration

The Authors

Klaus F. Zimmermann, Bonn University, Bonn, Germany, IZA, Bonn, Germany, and DIW Berlin, Berlin, Germany

Amelie F. Constant, DIW DC, Washington, DC, USA, Georgetown University, Washington, DC, USA, and IZA, Bonn, Germany

Liliya Gataullina, IZA, Bonn, Germany

Acknowledgements

JEL classification – F22; J15; J61. Financial support from Volkswagen Foundation for the IZA project on “The Economics and Persistence of Migrant Ethnicity” is gratefully acknowledged. The authors also thank Don DeVoretz and two anonymous referees for helpful suggestions on earlier drafts.

Abstract

Purpose – The purpose of this paper is to study the determinants of naturalization of non-EU immigrant household heads with a fresh look at the role of integration and ethnicity.

Design/methodology/approach – Employing data on immigrant household heads from the German Socioeconomic Panel differentiation is made among those who already have been naturalized, those who plan to take citizenship, and those who do not have citizenship and do not want it, using multinomial probit models. The subject scope includes literature on naturalization, ethnicity, and integration.

Findings – A robust finding is that German citizenship is very valuable to female immigrant household heads and the generally better educated, but not to those educated in Germany. The degree of integration into German society has a differential effect on citizenship acquisition. While a longer residence in Germany has a negative influence on actual or future naturalization, arriving at a younger age and having close German friends are strong indicators of a positive proclivity to citizenship acquisition. Likewise, ethnic origins and religion also influence these decisions. Muslim immigrants in Germany are more willing to become German citizens than non-Muslim immigrants, but there are also fewer German citizens among Muslims than among non-Muslims.

Research limitations/implications – Future research should also investigate the second-generation naturalization proclivities and those of illegals.

Practical implications – Allowing for dual citizenship helps generate more naturalizations among Muslims.

Originality/value – The paper provides a test of the relative importance of the integration approach in comparison with the ethnicity model; demonstrating that integration in German society has a stronger effect on naturalization than ethnic origin and religion.

Article Type:

Literature review

Keyword(s):

Citizenship; Integration; Germany; Immigrants; Ethnic groups.

Journal:

International Journal of Manpower

Volume:

30

Number:

1/2

Year:

2009

pp:

70-82

Copyright ©

Emerald Group Publishing Limited

ISSN:

0143-7720

1. Introduction

Immigrant naturalization remains a much-debated issue in German immigration politics. After long denying its status as an immigrant country, the German government of 2001 took a pioneering stance by proposing the Immigration Act (Zuwanderungsgesetz) to the Parliament (Bundestag), which only came into effect on January 1, 2005 after a number of compromises in the political process. The Act allows foreigners to obtain citizenship with a much more proactive stance towards integration; immigrants should receive 650 hours of language instruction, demonstrate knowledge of the German constitution and take an oath of allegiance to the Basic Law of the Federal Republic of Germany, inter alia [1]. Since 2000, immigrants from some countries like Turkey also need to sign a document renouncing their previous citizenship and promising that they will not acquire a second citizenship after they take the German one.

Currently, immigrants can apply for German citizenship after eight years of residency in Germany, with several exceptions allowing the naturalization process to begin as early as three years after arrival if one is married to a German citizen. Bloodlines (ius sanguinis a patre et a matre) are no longer the only route to citizenship; the law of soil (ius soli) is also implemented for children. Additional eligibility requirements are: assurance of one's own subsistence and the subsistence of dependents without recourse to benefits, adequate knowledge of German, of the legal system, the society and living conditions in Germany, plus no criminal record. Perhaps one of the most publicly discussed issues caused by the new legislation is the naturalization test (Einbürgerungstest). Effective on September 1, 2008, all immigrants have to take and pass the test before acquiring citizenship. While proponents present it as a natural part of the integration process, opponents criticize it for being too demanding.

Before the reform, even up to 15 years of residence (ius domicilii) and stiff monetary fees (up to 5,000 DM at times) did not give immigrants the “right” to citizenship, which was up to the discretion of German officials. Although since the 1990s the naturalization process has become less stringent, many eligible immigrants choose not to become German citizens. However, immigrant citizenship ascension rose after the new citizenship law was enacted. In 2000 alone 186,688 immigrants acquired German citizenship; in contrast, during the 1980s only 133,000 foreigners were naturalized over the entire decade. In 2000 naturalization instances peaked after a four decade rise, but dropped again in 2005 to 117,241 cases[2]. German officials announced in July 2007 that the number of naturalized immigrants had risen to 124,832 in 2006, an increase of 6.5 percent over the previous year (Deutsche Welle, 2007).

Despite numerous cases of immigrant naturalization, still there are many legal foreigners residing in Germany who have decided not to naturalize or who have postponed their naturalization. To visualize the number of people who do not acquire German citizenship in spite of being qualified, we calculate some rough figures of the number of immigrants who qualify to receive German citizenship in the years 2004 and 2005 and compare these numbers to the actual naturalization statistics (see Table I).

When the minimum requirement for length of residency, the time it takes to complete the naturalization process and the yearly outflow of immigrants are taken into consideration, the predicted number of immigrants who arrived in Germany in 1997 and were eligible for German citizenship in 2005 is 391,460. This is three-and-a-half times higher than the actual number of immigrants (117,241) who naturalized during that year. This 30 percent ascension rate is much lower than, for instance, in Sweden and Canada (both over 70 percent) or the US (slightly less than 50 percent). In fact, the actual difference between the number of people eligible to acquire German citizenship by 2005 and the number of immigrants who acquired German citizenship during that year might even be larger, as there are many other immigrants who were nominally qualified for German citizenship prior to 2005, but apparently postponed their naturalization.

Why do some eligible legal immigrants naturalize while others do not, and are there any internal or external barriers to this process? This paper studies the determinants of naturalization among immigrants who do acquire German citizenship, immigrants who have not obtained citizenship but are willing to receive it in the future, and immigrants who do not want to acquire German citizenship. In particular, we measure the impact of integration into society and ethnicity (including religion) on the probability to naturalize. In the following section we review the relevant literature and develop our research question. In section 3 we present the data, variables and the model. In section 4 we summarize the results of the empirical analysis and conclude in section 5.

2. Relevant literature and theoretical considerations

The naturalization of immigrants has been traditionally considered by economists within the framework of economic integration into the destination society. The interest of most economic research on naturalization has been directed towards labor market effects of citizen acquisition. Evidence about the impact of naturalization on immigrants' integration into the local labor markets and on wages is found in North American as well as European societies including Germany (Bratsberg et al., 2002; Constant and Zimmermann, 2005; DeVoretz and Pivnenko, 2005; Fougère and Safi, 2008; Steinhardt, 2008). However, there are also a few studies that find no relationship, or even a negative one, between naturalization and immigrants' economic success in these countries (Bevelander, 2000; Constant, 1998; Mata, 1999).

Few economists recognize in their modeling of economic effects of citizenship acquisition that the naturalization of immigrants might be endogenous (DeVoretz, 2008). Whether or not to naturalize in the destination country is a choice that immigrants make at some point after immigration. Their decision depends on various socioeconomic, individual and demographic factors, and takes into consideration the opportunity to have a double citizenship (Constant and Zimmermann, 2007; DeVoretz and Pivnenko, 2005; Mazzolari, 2006; Diehl, 2002). A far more extensive analysis of naturalization as an endogenous decision exists in sociological research. Sociologists have shown that the naturalization decision depends not only on the individual demographic and socioeconomic characteristics of immigrants (e.g. Bernard, 1936; Evans, 1988), but also on the extant characteristics found in the immigrants' sending country as well as the immigrants' ethnic group (e.g. Portes and Cutris, 1987; Yang, 1994).

Our study emphasizes the role of the host country and the particular ethnic group under consideration. To understand the dynamics of citizenship acquisition among non-European Union (EU) immigrants, we study differences in naturalization proclivities among Turkish and ex-Yugoslav immigrants, the two largest immigrant groups in Germany. Unlike other countries that sent large numbers of migrants to Germany, Turkey and the former Yugoslavia are still non-EU members, and, therefore, do not enjoy the political and mobility privileges of citizens of European Member States.

In addition, our study focuses on both the decision to actually naturalize and the immigrants' willingness to acquire German citizenship sometime in the future. It is important to distinguish immigrants who do not have and do not want German citizenship from immigrants who do not have but would like German naturalization. Willingness to naturalize, or lack of thereof, could demonstrate the degree of closeness or distance to the home or host country; and help evaluate immigrants' general satisfaction with German society. Acquiring German citizenship, especially when the degree of willingness to naturalize in the future is taken into consideration, is an indicator of how smooth the process of naturalization is, and whether there are any barriers that prevent immigrants from naturalizing. If an immigrant naturalized, this may also be a sign of stronger assimilation with German society. The difference between these motives is important, as they might be defined by a different set of characteristics. We hypothesize that immigrants who have not naturalized, but would like to do it in the future, are more similar to immigrants who have already acquired German citizenship than to immigrants who do not want to naturalize at all.

It is important to understand the relationship between naturalization and integration, because a clear perception of this relationship is useful for policymaking directed at helping immigrants to become full-fledged members of the destination societies, with equal rights and responsibilities. Integration should indicate the degree of interaction immigrants have with the host society measured, for instance, by German schooling, length of residency and closeness of relationships with Germans. How the economy of the origin country compares to the economy of the host country and what kind of citizenship laws the home country has, also exert an important role in immigrants' decision to naturalize. To learn about the effect of ethnicity on the immigrants' naturalization proclivities, we look at how migrants' origin and religion relate to their citizenship status. We are particularly interested in finding out if being a Muslim defines the choice to naturalize, because the question of cultural and religious differences between the dominant Christian German society and Muslim minorities is often raised in Germany.

3. Dataset, variables, statistics and modeling

We use the most recently available 2005 wave of the German Socio-Economic Panel (GSOEP). The GSOEP reports extensively on ethnic groups of immigrants who started arriving in Germany as “guest workers” in the late 1950s and 1960s, such as Turks, Greeks, Italians, Spaniards and people from the former Yugoslavia. The survey also includes those immigrants who arrived after 1973 when the guest-worker program was terminated. Our sample only contains foreign-born immigrants who came from Turkey or from the former Yugoslavia. These legal immigrants are the only two sizable groups in the GSOEP who are not part of the EU and therefore should have a significant incentive to acquire German citizenship. Italians, Greeks and Spaniards in the GSOEP dataset have actually not changed their citizenship, which is not surprising given their limited advantage for such a move. Even though it would be interesting to compare proclivities to naturalize between first- and second-generation immigrants, this paper concentrates on analyzing how attachments to the country of origin influence the naturalization decision of first-generation immigrants. The second-generation immigrants are first German-born and qualify under different clauses and second have not spent as significant a part of their lives outside of the host country as the first-generation has; therefore, their decision to naturalize will be based on different factors.

Our sample is also restricted to those respondents who have been in Germany for more than eight years and therefore pass the residency requirement for citizenship acquisition. Even though eight years are not a clear-cut restriction applicable to all immigrants – in exceptional cases like in intermarriage it is three years – they are required for otherwise eligible immigrants to naturalize if they want to. Thus, limiting our sample to respondents who spent more than eight years in Germany, we consider only those immigrants who lived long enough in Germany to qualify for citizenship, even though some of the selected immigrants may have qualified to apply for citizenship much earlier than eight years after arrival, and others may not have even applied after that. Moreover, because citizenship acquisition behavior of the family is probably strongly related to the head of the family we concentrate our analysis on household heads only. This restricts our sample to 387 immigrant household heads. Among them nobody acquired citizenship after 2000, the period under the new German citizenship legislation. This implies that the implementation of the new German citizenship law had no effect on the sampled immigrants' citizenship ascension decision.

The dependent variable in our econometric models distinguishes among three types of immigrants, according to their citizenship status:

  1. immigrants who have acquired German citizenship;
  2. immigrants who express a willingness to acquire German citizenship in the future; and
  3. immigrants who do not have and do not want to acquire German citizenship in the future.

We further consider independent variables in three groups, namely:

  1. individual and human capital characteristics such as age, gender, marital status and total years of education, measures capturing;
  2. ethnicity using dummy variables for country of origin and religion; and
  3. integration – integration variables include education in Germany (a dummy), length of residence in Germany (in years) and having native Germans as close friends (a dummy).

We further use dummy variables for whether a person spent more than 15 years in Germany or not and if one arrived before 1973. The “15 years in Germany or longer” dummy separates immigrants who were also eligible for naturalization prior to the 2000 reform from those immigrants who are eligible to acquire German citizenship only by the new legislation. Immigrants who were not eligible for naturalization before the reform and became eligible after the reform may have turned more positive towards citizenship acquisition. We can identify this optimism in the attitudes towards future naturalization. By controlling for immigrants arriving in Germany prior to 1973 we acknowledge cohort differences between immigrants of the same origin. Until 1973 most immigrants from Turkey or ex-Yugoslavia came to Germany as guest workers, while those arriving later came mostly as family members of individuals who had settled in Germany earlier.

Table II reports the means and standard deviations of the key variables used for the whole sample, and by gender, ethnicity and religion. Of the individuals in our sample, 24 percent are citizens, and 18 percent plan to apply for German citizenship. Thus, over 50 percent of immigrants express no willingness to acquire German citizenship. Interestingly, there are more German citizens among female (38 percent) than among male household heads (20 percent); about the same percentage of them (18 percent) wants to apply for citizenship in the future. The percentage of citizens among Muslims is significantly lower (20 percent) than that among non-Muslims (30 percent), but, on average, Muslims are more willing to acquire German citizenship in the future (21 percent) than non-Muslims (13 percent).

More than a third of our sample (36 percent) originates in the former Yugoslavia, while the rest of the sample comes from Turkey. Sampled are 58 percent Muslims, of whom 84 percent are Turks and the rest are from the former Yugoslavia. Among non-Muslims, 33 percent are Turks. This relatively high number of non-Muslim Turks can be explained first by the fact that minority groups have a much higher emigration rate than the majority in the country of origin. Evidently, a higher percentage of Armenians and Orthodox Christians arrived in Germany from Turkey than the 1 percent which is found in Turkey itself. Second, the vast majority of these immigrants had spent more than 15 years in Germany at the time of the survey and therefore had a lot of time to reconsider or assimilate their religious beliefs to German ones.

Table II further reveals that 25 percent of the sample are females, 84 percent are married and the mean arrival age was 19. Immigrant household heads are, on average, 49 years old and have acquired ten years of education. Nearly 40 percent got some German education and 44 percent have close German friends. Women are younger, arrived at a younger age, and have more German education and more German friends. More than half of the sample arrived before 1973 and 90 percent have been in Germany for more than 15 years. Until 1973 most immigrants arrived as guest workers, recruited to help with the shortage of native blue-collar workers. In 1973 the recruiting program ended with the recession caused by the oil crisis; those arriving afterwards were mostly family members of previously settled migrant workers. The variable “more than 15 years in Germany” controls for potential cohort differences and earlier citizenship legislation on the behavior of immigrants.

4. Empirical results

Table III presents the results of multinomial probit models of citizenship acquisition. The reference category of the dependent variable is immigrants who do not have and do not plan to acquire German citizenship. The Base Model (columns (1) and (5)) is the bare minimum estimation based on standard individual characteristics such as gender, marital status and total years of education. In addition to these basic characteristics, the Integrationist Model (columns (2) and (6)) includes several indicators that capture how an immigrant has been exposed and adjusted to German society. The Ethnicity Model (columns (3) and (7)) is the Base Model augmented by the migrants' ethnic origin and religion. Finally, the Complete Model (columns (4) and (8)) encompasses all characteristics to gauge their joint effect on citizenship acquisition.

Column 1 documents a significant relationship between the immigrant household heads' basic characteristics and their plans to acquire German citizenship. Clearly, female heads are more likely to want to acquire German citizenship in the future than their male counterparts, compared to the reference category of those not wanting to acquire German citizenship. Migrant female household heads are also more likely to have already obtained German citizenship than migrant male heads (column (5)). This is consistent with Table II and earlier findings (Diehl, 2002). While marriage positively and significantly affects plans to obtain citizenship in the future, it has no statistical significance on the probability to have already acquired German citizenship (given the reference category).

Consistent with previous research, we find that total years of education have a significant and positive impact on future plans to naturalize and an even stronger impact on the actual possession of citizenship. This is because with education immigrants realize that the German passport not only helps to avoid visa issues and military service in the home country (for men), but it also empowers them in the form of voting rights, access to high-end jobs, responsible living and a better future for their children. The persistence of some of these effects, however, varies when controlling for additional individual characteristics.

Our results show that it is important to account for the degree of immigrants' integration into the host society. The Integrationist Model in columns (2) and (6) demonstrates that having close German friends positively influences the immigrants' desire to acquire citizenship as well as the likelihood of being naturalized. As expected, we also find that the younger a person is at the time of arrival to the host country the more inclined one is to apply for citizenship in the future (column (2)) and more likely to have acquired citizenship (column (6)). Quite surprisingly, however, our results reveal that a longer duration of stay in Germany is negatively associated with both the willingness to naturalize in the future and with having German citizenship. Immigrants who came to Germany before 1973 or those who have been in Germany for more than 15 years are less likely to want to acquire German citizenship in the future (column (2)). The probability of naturalizing (column (6)) is also negatively affected by more than fifteen years of residence. This may reflect the fact that prior to the 1990s it was quite strenuous for foreigners to acquire German citizenship. By the time the citizenship legislation was relaxed, many immigrants might have become accustomed to life in Germany without German citizenship and being older they did not want to assume the costs of naturalization (monetary or psychic). The more recent immigrant arrivals, on the other hand, may still consider German citizenship beneficial for their life and future in Germany and therefore want to acquire it at the first opportunity. It is also possible that the psychology of those who arrived before 1973 as guest workers impedes them from “becoming Germans”; their whole wherewithal, mentality and demeanor may still be associated with the temporary program and the illusion of returning. Those who came under the family reunification scheme, however, may be more realistic in considering Germany home and wanting to ascend to citizenship.

The Integrationist Model also demonstrates that while education in Germany does not significantly correlate with the immigrants' willingness to acquire German citizenship in the future (column (2)), it is positively related to the probability of already holding German citizenship. For example, an immigrant who has some education in Germany is significantly more likely to have German citizenship than someone without any German education in relation to the reference category. However, this effect disappears once we control for additional individual characteristics in the Complete Model in column (8). The reason why we find no significant effect of education in Germany on the willingness to acquire citizenship before and in the future may relate to the fact that once Turks or ex-Yugoslavs receive education in Germany they know they become more competitive in the labor markets of other European countries, as well as in their countries of origin. Therefore, the German citizenship may have no particular value for them.

Results from the Ethnicity Model in columns (3) and (7) (Table III) show that origin and religion also correlate with both the willingness to have German citizenship and the actual possession of it. Muslim immigrants are significantly more likely to want to acquire citizenship, but less likely to already have it than non-Muslims. Ex-Yugoslavs are no less eager to have German citizenship one day than non-Muslim Turks are. However, they are significantly less likely to already hold citizenship than non-Muslim Turks. These results change only slightly when additional controls for the immigrants' level of integration are added in the Complete Model (columns (4) and (8)).

Our findings point to the existence of certain institutional or cultural barriers hindering Muslims and ex-Yugoslavs from naturalizing. One of the plausible barriers is the legal requirement to renounce their own citizenship. Despite appreciating all the comfort and perks that German citizenship offers, it may be particularly difficult for Muslims to renounce a citizenship related to a Muslim society and naturalize in a country with a Christian society. For non-Muslims in our reference category, this process is psychologically less demanding, as they do not have to make these types of religious considerations.

The large Turkish community is relatively skilled at creating institutions that can assist Turks in the lengthy process of naturalization and guide them through German red tape. The ex-Yugoslav community is more diverse and less organized in this sense, which may relate to our second finding that immigrants coming from the former Yugoslavia have lower rates of citizenship than non-Muslim Turks do.

We finally investigate the overall performance of the models using likelihood-ratio tests for excluding groups of variables affiliated with a particular model (see Table IV). The first row deals with the simple Integrationist Model (column (1)) and the simple Ethnicity Model (column (2)), comparing their likelihood values with the likelihood value of the Base Model. The χ2 test-statistics clearly reject the Base Model in both cases. In the second row we exclude the integration factors (column (1)) or the ethnicity factors (column (2)) from the Complete Model. Again, the likelihood-ratio tests indicate that both sets of variables matter, and both models have their contribution. We, however, also find that the Integrationist Model seems to have more power than the Ethnicity Model.

5. Conclusion

Less than a quarter of the eligible immigrants from Turkey and the former Yugoslavia are German citizens. Previous conflicting findings on the impact of naturalization on successful economic integration in the host country (even after controlling for human capital and individual characteristics), prompt us to study the determinants of naturalization with a fresh approach. We use the 2005 wave of the GSOEP to study the effect of ethnicity and integration in the German society on the probability of citizenship acquisition for these two sizable non-EU immigrant groups. We consider three types of legal eligible immigrants at the level of household head; those who have already acquired German citizenship; those who have not yet naturalized, but would like to in the future; and those who do not have and do not want to obtain German citizenship. We are particularly interested in understanding the direction of the relationship between immigrants' integration in Germany and their decision to naturalize, as well as in analyzing the impact of the immigrants' ethnicity (including religion) on the choices of German citizenship acquisition.

Our empirical analysis indicates that immigrants who have naturalized and immigrants who would like to acquire German citizenship one day are different from immigrants who do not want to acquire German citizenship. Specifically, female household heads are both more likely to want to acquire and to already have acquired German citizenship than their male counterparts. This finding is robust across several specifications and shows that German citizenship is very valuable to these non-EU immigrant women. Moreover, we find that married immigrants are more likely to want to have German citizenship, but there is no difference between married immigrants and those living alone in their actual citizenship status. Our results also show that more educated immigrants are more likely to want to naturalize in the future or to have already naturalized.

We also find a strong relationship between the immigrants' integration into the German society and the probability of naturalizing. Having close German friends is one of the strongest signs of a positive proclivity to both actual and future German citizenship acquisition. The younger immigrants are at arrival, the greater the odds are of being naturalized or wanting to naturalize eventually. Education in Germany, however, correlates only marginally with citizenship acquisition, which is consistent with research on ethnic identity (Zimmermann et al., 2008). Much to our surprise, our empirical analysis indicates that the length of stay in Germany negatively affects the immigrants' willingness to naturalize or to have already naturalized. We explain this finding by the fact that immigrants who have resided in Germany for a long time (more than 15 years) without German citizenship learn to live without it, and see no advantage in changing their citizenship status. After all, as legal immigrants they have all rights but political. Another possible explanation is that those immigrants who were recruited as guest workers before 1973 have kept the mentality and psychology of the temporary program and are lulled by the thought of returning back to their homeland.

The ethnicity of immigrant household heads, as manifested by country of origin and religion, is another important determinant of their decision to naturalize. Our findings suggest that those immigrants from the former Yugoslavia and Muslims are more willing to naturalize, but are less likely to already have naturalized than non-Muslim Turks. Similarly, we find that Muslim immigrant household heads in Germany are more willing to become German citizens than non-Muslim heads. Yet there are fewer German citizens among Muslims than among non-Muslims. These results point to the existence of certain institutional or cultural barriers faced by certain ethnic and religious immigrant groups when contemplating the acquisition of German citizenship.

ImageTable I Potential and actual numbers of naturalized immigrants in Germany
Table I Potential and actual numbers of naturalized immigrants in Germany

ImageTable II Descriptive sample statistics of foreign-born household heads in 2005
Table II Descriptive sample statistics of foreign-born household heads in 2005

ImageTable III Multinomial probit models of citizenship acquisition
Table III Multinomial probit models of citizenship acquisition

ImageTable IV Likelihood-ratio test of integration and ethnicity effects
Table IV Likelihood-ratio test of integration and ethnicity effects

Notes

  1. The first reform to the German nationality law of 1913 came into effect on January 1, 2000. Dual citizenship, under certain circumstances, is allowed to all EU nationals and to the children of bi-national marriages.

  2. These statistics do not include the naturalization of ethnic Germans. Unlike other immigrants, ethnic Germans are guaranteed the immediate right to citizenship upon arrival in Germany. We, therefore, limit our discussion to the citizen acquisition process of ethnically non-German immigrants.

References

Bernard, W.S. (1936), "Cultural determinants of naturalization", American Sociological Review, Vol. 1 No.6, pp.943-53.

[Manual request] [Infotrieve]

Bevelander, P. (2000), Immigrant Employment Integration and Structural Change in Sweden, 1970-1995. Lund Studies in Economic History 15, Lund University Press, Lund, .

[Manual request] [Infotrieve]

Bratsberg, B., Ragan, J.F., Nasir, Z.M. (2002), "The effect of naturalization on wage growth: a panel study of young male immigrants", Journal of Labor Economics, Vol. 20 No.3, pp.568-97.

[Manual request] [Infotrieve]

Constant, A. (1998), “The earnings of male and female guestworkers and their assimilation into the German labor market: a panel study 1984-1993”, PhD dissertation, Vanderbilt University, Nashville, TN, .

[Manual request] [Infotrieve]

Constant, A., Zimmermann, K.F. (2005), “Legal status at entry, economic performance, and self-employment proclivity: a bi-national study of immigrants”, IZA Discussion Paper No. 1910, IZA, Bonn, .

[Manual request] [Infotrieve]

Constant, A., Zimmermann, K.F. (2007), “Circular migration: counts of exits and years away from the host country”, IZA Discussion Paper No. 2999, IZA, Bonn, .

[Manual request] [Infotrieve]

DeVoretz, D.J. (2008), "The economics of citizenship: a common intellectual ground for social scientists?", Journal of Ethnic and Migration Studies, Vol. 34 No.4, pp.679-93.

[Manual request] [Infotrieve]

DeVoretz, D.J., Pivnenko, S. (2005), "The economic causes and consequences of Canadian citizenship", Journal of International Migration and Integration, Vol. 6 No.3-4, pp.435-68.

[Manual request] [Infotrieve]

Deutsche Welle (2007), “Germany allows more people to hold dual citizenship”, available at: dw-world.de (accessed 31 August 2007), .

[Manual request] [Infotrieve]

Diehl, C. (2002), "Wer wird Deutsche/r und warum? Bestimmungsfaktoren der Einbürgerung türkisch- und italienischstämmiger junger Erwachsener - Ergebnisse des Integrationssurveys des BiB", Zeitschrift für Bevölkerungswissenschaft, Vol. 27 No.March, pp.285-312.

[Manual request] [Infotrieve]

Evans, M.D.R. (1988), "Choosing to be a citizen: the time-path of citizenship in Australia", International Migration Review, Vol. 22 No.2, pp.243-64.

[Manual request] [Infotrieve]

Fougère, D., Safi, M. (2008), "The effects of naturalization on immigrants employment probability (France, 1968-1999)", IZA Discussion Paper No. 3372, available at: SSRN: http://ssm.com/abstract=1294533 or DOI: 10.1111/j.0042-7092.2007.00700.x, .

[Manual request] [Infotrieve]

Mata, F. (1999), "Patterns of acquiring citizenship", in Halli, S., Driedger, L. (Eds),Immigrant Canada: Demographic, Economic and Social Challenges, University of Toronto Press, Toronto, pp.163-82.

[Manual request] [Infotrieve]

Mazzolari, F. (2006), “Determinants and effects of naturalization: the role of dual citizenship laws”, mimeo, available at: www.socsci.uci.edu/∼fmazzola/Research/Mazzolari_dual.pdf, .

[Manual request] [Infotrieve]

OECD (2007), International Migration Outlook, SOPEMI, OECD, Paris, .

[Manual request] [Infotrieve]

Portes, A., Curtis, J.W. (1987), "Changing flags: naturalization and its determinants among Mexican immigrants", International Migration Review, Vol. 21 No.2, pp.352-71.

[Manual request] [Infotrieve]

Steinhardt, M.F. (2008), “Does citizenship matter? The economic impact of naturalizations in Germany”, HWWI Research Paper 3-13, HWWI, Hamburg, .

[Manual request] [Infotrieve]

Yang, P.Q. (1994), "Explaining immigrant naturalization", International Migration Review, Vol. 28 No.3, pp.449-77.

[Manual request] [Infotrieve]

Zimmermann, L., Gataullina, L., Constant, A., Zimmermann, K.F. (2008), "Human capital and ethnic self-identification of immigrants", Economics Letters, Vol. 98 No.3, pp.235-9.

[Manual request] [Infotrieve]

About the authors

Klaus F. Zimmermann is a Professor of Economics at Bonn University, Director of the Institute for the Study of Labor (IZA Bonn), President of the German Institute for Economic Research (DIW Berlin), Honorary Professor of Economics at the Free University of Berlin, and Honorary Professor at the Renmin University of Peking. His current research interests are in migration, labor economics and population economics with a particular focus on ethnicity and identity. He is the author or editor of 33 books and 95 papers in refereed research journals and 108 chapters in collected volumes. Klaus F. Zimmermann is the corresponding author and can be contacted at: zimmermann@iza.org

Amelie F. Constant is the Executive Director of DIW DC, IZA's Deputy Program Director of Migration, and a visiting professor at Georgetown University. Her research is on migration in Europe and the USA, assimilation issues, immigrant entrepreneurship, ethnic identity, gendered differences in labor market, occupational mobility, risk-attitudes, brain-drain, remittances, and the relationship between schooling quality and earnings. She has published her work in many journals, has written many book chapters, and co-edited the book How Labor Migrants Fare?.

Liliya Gataullina is a Research Affiliate at IZA, Bonn. She is working on migration and ethnicity issues.