What’s the matter with Rotterdam? This is a question I asked in a 2017 lecture (available to view at www.mmg.mpg.de), when trying to figure out how and why the city seems to disrupt common contemporary narratives concerning migration and cities. That is, social scientists since Simmel have postulated that cities are largely incubators of cosmopolitanism, or openness (if only indifference) to socio-cultural differences. It is often presumed that such openness goes together with an acceptance of ethnic diversity and immigration. Opinion polls and ethnographic research in cities usually bears out this presumption. Hence, it comes as surprising if not shocking to learn that in super-diverse Rotterdam – with over 50% of its population stemming from some 180 nations – the urban model of cosmopolitan incubator seems to fail. Authors in this collection have pointed to developments in Rotterdam by way of negative reactions to diversity, substantial voting for rightwing, anti-immigrant parties, and an ‘unhappy version’ of super-diversity in which the growth of a disapproving atmosphere has led to sharper ethnic boundaries, retreat into white enclaves, and low levels of white-ethnic minority social contact. Indeed, what’s the matter with Rotterdam?

In this volume we have read of how, despite – or because of? – its remarkable levels and kinds of diversity, Rotterdam is the Dutch city with the highest number of voters for Geert Wilders’ populist PVV (Partij voor de Vrijheid or Party for Freedom), and where the rightwing Leefbaar Rotterdam (Livable Rotterdam) party, heirs of Pim Fortuyn’s anti-immigrant movement, is also the City Council’s largest. How and why has this particular configuration (a high degree of super-diversity combined with strong right-wing sentiments) arisen? There is no single answer to such a complex situation and set of factors. In order to attempt a comprehensive set of answers, we would need an even broader analysis than that offered by this extensive volume concerning the historical interplay of the city’s demography (not just ethnicity and migration background, but age, education and income), socio-economics and labour market, urban policies, political campaigns and public debates. An important part of such an inquiry would have to be the examination of what we might call conditions of diversity, or complex social environments, and how they channel or influence particular outcomes by way of social engagement, public attitudes and political climate (Vertovec 2015).

For studying conditions of diversity and their impacts, initially one can turn to conventional theories to seek answers to this seeming puzzle as to why anti-diversity proponents are so successful in the super-diverse city of Rotterdam. For instance, ethnic competition theory holds that ethnic/racial groups that are in proximity and that hold relatively equal social-structural positions become antagonistic as they contend for scarce resources such as jobs, housing, schools and state support (cf. Olzak and Nagel 1986; Cunningham 2012; Gonzalez-Sobrino 2016). In Social Psychology, group threat theory suggests that large numbers of ethnic minorities often lead to high levels of resentment, anger and fear among Whites (see for instance Tajfel and Turner 1979) or in Rotterdam’s case, ‘Autochtoons’. This is thought to arise from threats to identity and fear among Whites with regard to their potential loss of numerical weight, group status and political or symbolic dominance. Such feelings of threat, moreover, may lead directly to increased support for conservative ideologies and support for anti-immigration policies (Craig et al. 2018). These two rather classic theories, ethnic competition and group threat, are likely relevant to social and political dynamics in Rotterdam – but they cannot be regarded as entirely explanatory. Further reasons and dynamics need to be considered.

For instance, other, more context-specific demographic or geographical factors might be at play. One might be the impacts of small but rapid diversification. One of the early ethnic competition theorists, Susan Olzak (1992), postulated that ethnic threat – in terms of both a sense of heightened competition and vulnerable group status – among a majority population is more likely triggered by recent, albeit limited, increases in ethnic minority sizes than by the stable presence of a large set of minority groups. That is, sudden changes in ethnic diversity, however small, are enough to trigger fear and dismay among a current majority. More recently, as H. Robert Outten and his colleagues (2012: 15) point out, ‘existing research has demonstrated that both actual increases in the relative size of the non-White population and Whites’ perceptions of relative group size are related to appraisals of threat.’ Eric Kaufmann (2014) similarly demonstrates that White toleration of ethnic minorities is reduced by changes in diversity: ‘Rapid ethnic change, especially in places with limited experience of prior diversity, tends to be associated with radicalised White opinion and elevated far-right voting’ (Ibid.: 272). In the United Kingdom, Kaufmann shows that support for the British National Party (BNP) is strongest in wards that were relatively White British in 2001 but that experienced a fast increase in ethnic minority share – although still rather small relative to other parts of London – during the 2000s. For example, a number of wards in outer London or Essex boroughs such as Redbridge, Barking and Dagenham or Thurrock changed quickly with respect to the proportion of ethnic minorities; these subsequently witnessed high BNP support. In the Netherlands, Michael Savelkoul et al. (2017) similarly found that in areas that have undergone recent increases in ethnic minorities, there is a greater likelihood of voting for PVV.

The ‘halo effect’ represents another current theory about surges in rightwing politics linked to the intensification of feelings of threat posed to some by diversity and diversification. This relates to the geography of diversity and anti-diversity attitudes. ‘Halo’ refers to zones that comprise a ring, arc or edge outside of a highly diverse area: if these halo zones are ones of high White concentration, anti-diversity attitudes may become increasingly salient. As Jens Rydgren and Patrick Ruth (2013: 718) describe, ‘xenophobia and immigration-negative attitudes are most common in areas close to neighbourhoods with a high proportion of immigrants, and not within such neighbourhoods; making such areas even more likely breeding grounds for radical right-wing populist mobilization.’ In this way, too, Kaufmann (2014: 272) points to anti-immigrant politics stemming from a ‘threat from diversity in one’s wider area’. ‘The presence of significant diversity in one’s city or local authority,’ he (Ibid.) surmises, ‘adds to threat perceptions because of the sense immigrants may soon introduce large-scale change into one’s locale.’ Kaufmann summarizes the Halo effect as ‘the fact that opposition to immigration is greatest when immigrants are close, but not too close’ (Ibid.).

In and around Rotterdam, these latter theories – small but rapid diversification and the halo effect – appear to have relevance. For example, two of the only Dutch municipalities in which a majority of votes went to Wilders’ PVV were Schiedam and Nissewaard: these are immediately adjacent to the North and South of the municipality of Rotterdam (but still part of a greater Rotterdam area). As we have learned throughout this volume, Rotterdam is super-diverse with a ‘Allochtoon’/foreign population of over 50% (of its total of some 638,221 in 2017; all statistics here from www.citypopulation.de). Nissewaard has comparatively very few foreigners (after a 2015 merger, the municipality is comprised of Spijkenisse [pop. 72,500] with a foreign population of 22% and Bernisse [pop. 10,490] with just 10% foreign). For Nissewaard – a municipality of predominantly Whites/‘Autochtoons’ immediately next to the super-diverse Rotterdam municipality – the halo effect might represent an apt theory of explanation for recent right-wing voting. In Schiedam (pop. 77,859), where the foreign or immigrant population doubled from some 20% in 1997 to 40% in 2016, the theory of small but rapid diversification (plus some degree of halo effect?) might have some explanatory bearing with regard to its high PVV turnout.

Within the municipality of Rotterdam itself, similar geographical dynamics might be at work with regard to the preponderant support for the Liveable Rotterdam party. At the centre of Rotterdam, the borough of Delfshaven (2016 pop. 75,445; all stats here from www.allecijfers.nl) is the city’s most diverse, with just 29.9% ‘Autochtoon’, 13.3% ‘Western foreigners’ and no less than 56.8% specifically ‘non-Western foreigners’. Adjacent to this is Rotterdam Centrum (pop. 32,925) with 45.6% Autochton and 36.6% ‘non-Western foreigners’. The boroughs with the highest number of Liveable Rotterdam representatives in the directly elected Area Committees of municipal government are Overschie, Prins Alexander, IJsselmonde and Charlois. These form a neat ring around Delfshaven and Rotterdam Centrum: hence the halo effect would seem to be at work here. Indeed, Overschie (pop. 16,195) has 62.7% Autochtoon and Prins Alexander (pop. 94,600) has 65.9% Autochtoon – so these are majority White boroughs on the edges of Rotterdam’s super-diverse core. However, IJsselmonde (pop. 59,630) has relatively high diversity with 52.2% Autochtoon, 9.7% ‘Western foreigners’ and 38.1% ‘non-Western foreigners’ while Charlois (pop. 66,180) in fact actually resembles Delfshaven with only 37% Autochtoon, 15.9% ‘Western foreigners’ and 47.1% ‘non-Western foreigners’. For these latter two boroughs, the halo effect theory seems irrelevant. Perhaps, if we had diachronic data, would these areas show small but rapid diversification as a source of right-wing voting? Or are there other factors to explain this anomaly – where IJsselmonde and Charlois present a microcosm of the Rotterdam conundrum of urban super-diversity combined with anti-diversity sentiments?

In order to get a better understanding of such dynamics (and to put such theories of diversity-driven attitudes to the test), I would suggest that much more qualitative – indeed, ethnographic – research is required in neighbourhoods with varying configurations of diversity in Rotterdam. In this way, we could get better descriptive insights into how super-diversity is perceived (from either within the super-diverse neighbourhood, from areas next door and from further afar), encountered, talked about and responded to behaviorally, interactively and politically. Further, we could get a deeper insight into the everyday workings of a range of super-diversity variables – gendered patterns, legal statuses, education levels, and more – instead of simply looking at the impacts of many ethnicities. This would also include a qualitative sense of racial discourses, concepts and meanings (probing the differences people perceive and act upon between the ‘Western’ and ‘non-Western’ foreigner categories) and the place of Muslim identifications in shaping public attitudes and political dynamics.

Another significant and related topic in need of further study in contexts like Rotterdam is that of the relationship between mobility and experiences of diversity in the city. As Han Entzinger rightly stresses in this volume, there is much to be gained from adopting the perspective of contact theory and its role in fostering the positive evaluation of others. However, what we don’t know much about is how those White/‘Autochtoon’ PVV or Liveable Rotterdam voters – who might harbor anti-diversity attitudes when thinking about the places they live – might nevertheless have positive encounters with ethnic minorities in their workplace, school or leisure activities. In other words, how might contact theory ‘work’ in some contexts away from home, but be overridden when people consider diversity and otherness in relation to their own dwellings and neighbourhoods? Again, more ethnographic fieldwork in Rotterdam and similar cities would tell us much about the nature of contacts, the role of inter-city mobility and the effects of exposure to differently diverse spaces around the city – and how these play into the shaping of public attitudes and voting behavior.

There is nothing ‘the matter’ or wrong with Rotterdam. As we have learned throughout this comprehensive volume, it is complex place with a tangled history of migration, work and housing, integration policy, local politics and everyday encounters. Each chapter has told us much about how cities work in general and how this one in particular has come to be as it is. There is still much to learn, however, about how Rotterdam shapes its residents, and how they shape the city.