Explaining Secessionism: What Do We Really Know About It?

In this thematic issue we discuss what we really know about the explanations for secessionism. Over the last few decades, an increasing number of new analyses on secessionism have appeared, regarding both its normative and its empirical dimensions. We can distinguish at least three types of research questions that categorise the current analyses of seces‐ sionism: normative, explanatory, and pragmatic. Political theorists work mainly on the moral and political right to uni‐ laterally secede, answering questions such as “under what conditions” this right is legitimate and “who” has this moral right (Requejo & Sanjaume‐Calvet, 2015; Sanjaume‐Calvet, 2020). Despite the importance of normative theories, these approaches do not provide explanations for secessionism, although most of them are built on implicit explanations of these phenomena. The field of explanatory theories of secession focuses mainly on the individual and/or aggregate pre‐ conditions and variables that correlate (or not) with the presence (or absence) of secessionist movements in specific ter‐ ritories. Through our general guiding question—”what do we really know about the explanations for secessionism?”—we try to disentangle the current explanations of secessionism by using empirical analyses, combining comparative politics and case studies. We bring together several different analytical perspectives, from political economy, nationalism, elec‐ toral behaviour, and institutional studies. Beyond these empirical perspectives, the issue puts forward some normative implications based on what we know and what we do not know about the existence of secessionist claims.


Introduction
Describing, explaining, and developing theories about secessions and secessionism is crucial for understanding these phenomena better and for developing potential solutions to them. In recent years, in a context of globalisation and growing illiberal trends (Acemoglu & Robinson, 2019;Levitsky & Ziblatt, 2018;Norris & Inglehart, 2019), certain intellectuals have upheld interpretations of secessionism that are sometimes based on misunderstandings, prejudices, or accepted ideas, rather than on specific empirical research. In this thematic issue we discuss what we really know about the explanations for secessionism. We address the subject by focusing on both individual and aggregate data in comparative politics, presented in a series of articles written by top researchers in this field.

A Growing Field of Scholarly Literature
Over the last few decades, an increasing number of new analyses on secessionism have appeared, regarding both its normative and its empirical dimensions. Two main interlinked factors explain the growing interest in this topic. Firstly, the fall of the Berlin Wall and the subsequent dissolution of the USSR, Yugoslavia, and Czechoslovakia led to the creation of several states, creating minorities and majorities in the new republics and fostering secessionism around the world (Lukic & Lynch, 1996). Secondly, since the 1980s, the academic debate on political liberalism has turned its interest to group rights and belonging (Bell, 1993;Requejo, 2001;Sandel, 1984). However, most normative and empirical analyses have generally followed parallel agendas, without a consistent epistemological balance existing between them.
We can distinguish at least three types of research questions that categorise the current analyses of secessionism: normative, explanatory, and pragmatic (see Table 1).
Political theorists work mainly on the moral and political right to unilaterally secede, answering questions such as "under what conditions" this right is legitimate and "who" has this moral right (Requejo & Sanjaume-Calvet, 2015;Sanjaume-Calvet, 2020). That is, the normative approach to secession generally focuses on the legality, legitimacy, and/or permissibility of this phenomenon from a political and moral standpoint.
Despite the importance of normative theories, these approaches do not provide explanations for secessionism, although most of them are built on implicit explanations of these phenomena. For instance, justcause theories (Buchanan, 1991(Buchanan, , 2004 assume that pro-independence movements emerge because of a perception of "lack of justice" among specific populations. There are thus moral criteria available to assess these demands and classify them as "vanity" or "just" secessions. For some reason that generally remains unexplained by these authors, "vanity" movements do not hold a valid claim, but often succeed in mobilising people for their cause. In a similar line of reasoning, "culturalist" theories assume that sub-national identities are the main driver of secessionism, but several sub-state identities without secessionist movements remain unexplained or are not considered as valid national identities.
This thematic issue explicitly focuses on explanatory approaches in order to consider the individual and collective causes of secessionism, and ends with some normative reflections based on the former explanatory empirical findings.

Some Analytical Features
The field of explanatory theories of secession focuses mainly on the individual and/or aggregate preconditions and variables that correlate (or not) with the presence (or absence) of secessionist movements in specific territories. This scholarly literature brings together quantitative and qualitative studies in political science with contributions from economics, sociology, international relations, historical studies, and political psychology. While the authors generally use the term preconditions to mean the necessary characteristics of each group (such as the existence of an identity and a territory), they generally use variables to refer to contextual and/or changing contingent aspects that might influence the probability of success of each movement in mobilising people to support secession. Additionally, some theories go further than this and: (a) point to these movements' immediate triggers of conflict; and (b) try to explain how successful they are (to achieve an independent state or to remain part of their parent state; see Figure 1).
These elements generally constitute the central argument of a given explanatory theory of secession (or specific study on this phenomenon), and they tend to interact with the other potential preconditions and/or variables in each author's analysis. Moreover, these elements are sometimes presented as the explanation for the upsurge of a certain movement, while at other times they are used to try and explain the degree of support for a movement or its success (both at individual and collec-tive levels). Obviously, in the empirical terrain, we usually observe a complex combination of these elements, one that might also change over time. It is evident that no single one of these theories is capable of encompassing a general or universal explanation of these kinds of movements across space and time.
Through our general guiding question-"what do we really know about the explanations for secessionism?"in this thematic issue we try to disentangle the current explanations of secessionism by using empirical analyses, combining comparative politics and case studies. We bring together several different analytical perspectives, from political economy, nationalism, electoral behaviour, and institutional studies. Beyond these empirical perspectives, the issue puts forward some normative implications (political theory) based on what we know and what we do not know about the existence of secessionist claims. In doing so, we aim to bridge the gap between normative and empirical approaches in the current literature on secessionism. This thematic issue includes contributions that analyse secessionism from individual, aggregate, and theoretical perspectives. The current Catalan context is the most frequently analysed empirical case in the articles that follow, although it is not the only one.
From an individual perspective which delves into the explanatory factors of secessionism, Jordi Muñoz refutes Piketty's "Catalan syndrome" through an analysis of the economic determinants of support for secessionism (Muñoz, 2021); Laia Balcells and Alexander Kuo work on "moderate voters," i.e., individuals that do not have a strong territorial preference (Balcells & Kuo, 2021); Robert Liñeira performs a case study on Scotland and the "voting shock" valence effects of elections as critical junctures (Liñeira, 2021); Juan Rodríguez-Teruel and Astrid Barrio analyse the role of party and voter polarisation as "ethnic outbidding" dynamics (Rodríguez-Teruel & Barrio, 2021); and the last contribution at the individual level

Grievances, economy, insƟtuƟons
Upsurge/rise of secessionism t0 t1 is from Jordi Argelaguet, who focuses on the impact of language on secessionism and anti-secessionism (Argelaguet, 2021). From an aggregate perspective, Francesc Amat and Toni Rodon's article, and Anwen Elias and Núria Franco-Guillén's contribution move beyond the micro level and include comparative data (Amat & Rodon, 2021;Elias & Franco-Guillén, 2021). Amat and Rodon introduce a large-N perspective that tests the "commitment problem" thesis using a dataset of regional autonomy; Elias and Franco-Guillén focus on pro-independence parties and their discourses during the secessionist rise that occurred between 2008 and 2018 in Catalonia. Both articles point to some relevant aspects and disregarded other aspects that are present in the scholarly literature, namely political discourses and the (lack of) credibility of territorial agreements.
Finally, from a theoretical perspective, José L. Martí and Lluís Pérez-Lozano discuss existing normative theories of secession (Martí, 2021;Pérez-Lozano, 2021). Martí describes the normative obstacles of legitimately redrawing borders, and proposes a potential solution based on disagreement and consensus; Pérez-Lozano, also working on the notion of legitimacy, reflects on the Quebec case and the role of constitutional firewalls in dealing with secessionist claims in liberal democracies.