Cycles of labour protests: public and private sector unions ’ contentious actions

Purpose – ThispaperaimstoexaminethecycleoflabourprotestsinSweden,comparingthecontentiousactions of trade unions in public and private sectors over 40 years. Prior studies have focused on industrial conflicts or labourprotests,butalong-termperspectiveonthebroadprotestrepertoireacrosssectorsislacking.Thegoalistotesttheargumentofdiversificationofactionrepertoireanddifferencesbetweenthepublicandprivatesectors. Design/methodology/approach – The authors apply the grievance and political opportunity theories of social movement research for explaining the cycles of labour protests and differences between sectors in Sweden over 40 years (1980 – 2020). The unique protest event data are combined with the official strike statistics. The research period includes the globalisation of the economy and two economic crises. Findings – Although unions in both sectors have decreased protest mobilisation over time, private sector unions have resigned the most, whereas public sector unions continue to mobilise a diverse set of protest actions. Swedish unions have not replaced strikes with other protest repertoires. The open opportunities have allowed them to use various protests as part of “ routine ” operations. Research limitations/implications – Protest event data are derived from newspapers, leading to an over-representation of large events in the urban areas. Future studies should combine data from newspapers with data about online protests. Originality/value – By thoroughly examining all protest events mobilised by all trade unions in different sectors over 40 years (1980 – 2020), the paper presents a comprehensive analysis of the cycles of labour protest. The findings should interest industrial relations and social movement scholars.


Introduction
Ever since Kelly (1998), concerned with unions' losing influence, suggested that trade unions needed to learn from and cooperate with social movements to revitalise themselves, scholars have directed attention towards other forms of labour protest strategies than strikes. Although it is well known that unions can mobilise members and non-members to political action (Kerrissey and Schofer, 2013;Lyon and Schaffner, 2021;Tarrow, 1993b) and combine different repertoires of contentious action (Gentile and Tarrow, 2009), existing studies still have some troublesome gaps in this regard.
First, prior research has seldom considered that unions operating in different economic sectors face different opportunity structures for protest mobilisation. Industrial relations in the public sector tend to be more regulated than those in the private sector. So, a sole focus on unions in one sector might give us a biased understanding of how the declining "old" repertoire (e.g. strikes) has been replaced or combined with a new one (e.g. various street actions) (Kelly, 2015). While some studies discuss how public-and private-sector unions use industrial action differently (Bechter et al., 2012;Hall and Soskice, 2001;Høgedahl and Ibsen, 2017), analysis of labour protest seldom makes such an explicit distinction. Although austerity-related mass demonstrations tend to be mobilised by public-sector trade unions, there are also indications of protest mobilisation by private-sector unions (Connolly and Darlington, 2012). Considering the potentially different outcomes of industrial conflicts (e.g. strikes) and more political mass demonstrations (Zarate Tenorio, 2014), it is important to know how public-and private-sector unions are using these strategies.
Second, studies of labour protests typically focus on one specific issue, such as a particular labour campaign or conflict (Heckscher and McCarthy, 2014;Heery et al., 2017;Holgate and Wills, 2018;Lee, 2015;Lopez, 2004;Tapia, 2013), or a specific event such as an economic crisis (Peterson et al., 2015;Psimitis, 2011;R€ udig and Karyotis, 2013). These studies give us in-depth insights into labour mobilisation in the context of constrained opportunities for activism, but they do not provide a comprehensive picture of protest cycles, as mobilisation during less turbulent times tends to be neglected. We argue that only a systematic long-term analysis of labour protests can reveal the more general patterns of unions' protest mobilisation, allowing us to show which unionsprivate-or public-sector onesare more active and how they combine different protest repertoires.
In this paper, we address these gaps by investigating protest mobilisation by unions organising employees in the private and public sectors over a 40-year period in Sweden. Considering that both public-and private-sector unions in Sweden faced diverse challenges from 1980 to 2020, we ask whether there are distinct differences between their collective action repertoires and, if so, what these differences are. The results of this comprehensive analysis of labour protest cycles in Sweden show that a general decline in industrial conflicts (i.e. strikes) has coincided with declining protest activism by unions. Public-sector unions, however, have become more active users of other types of protest than strikes in recent decades.
The paper proceeds as follows: we first review the literature on unions' protest mobilisation focusing on differences between the private and public sectors. This is followed by a description of the primary data for the study: the Swedish Protest Dataset and official strike statistics. We then present the descriptive empirical analysis of private-and publicsector union protests and discuss the implications of the findings.
Comparing public-and private-sector unions' action repertoires Described as the first modern social movement (Giugni and Grasso, 2019), the labour movement has been thoroughly studied. While most of the literature on labour-related collective action focuses on the mobilisation and outcomes of the most typical type of industrial conflictstrikes (Franzosi, 1989;Hodder et al., 2017;Vandaele, 2016;Velden et al., 2007), studies are increasingly investigating cooperation and cross-movement mobilisation between civil-society organisations and trade unions (Zajak, 2018) and the broader repertoire of union activism Kelly, 2015). Research on labour protests has often focused on one economic sector without comparing it with others. For example, some recent studies of collective protest events organised by precarious groups such as migrant labour (Alberti and Per o, 2018) or platform workers (Cini et al., 2022;Joyce et al., 2020;Tassinari and Maccarrone, 2020;Wood et al., 2021) provide empirical evidence of protest activism in the private sector. Similarly, research on unions' anti-austerity protests, especially on political and general strikes during the recent Great Recession (Barranco and Molina, 2021;Della Porta and Portos, 2020;Hamann et al., 2013Hamann et al., , 2016, show that at times of crisis, public-sector trade unions can mobilise large proportions of the population. We have some clear indications ER of public-and private-sector unions' ability to use other types of protest than strikes, but not of how public-and private-sector unions stand relative to each other. When exploring unions' protest mobilisation, we expect unions in the public and private sectors to make different strategic calculations regarding the potential gains accruing from protests, and therefore to use these strategies to different degrees. Although industrial conflicts in general are decreasing worldwide, public-sector employees still strike (Briskin, 2012;Mailand, 2019;Schmidt et al., 2019). In fact, previous research has emphasised the growing militancy of public-sector unions in Sweden (Th€ ornqvist, 2007) and elsewhere (Isaac et al., 2006). Public-sector employees' wages and working conditions are related to political decisions regarding, for example, welfare spending and social security regulations. Therefore, public-sector unions should be particularly motivated to engage in politics (Frege and Kelly, 2004;Kelly, 1998;Upchurch and Mathers, 2012). Neoliberal reforms, austerity measures and public-sector retrenchments also correlate with public-sector strikes (Briskin, 2012). Although private-sector unions could also gain from political decisions regulating labour market relations or specific economic sectors, the public sector is more directly affected by policy-making. Public-sector unions have strong incentives to take political action to influence the policy process, so we expect: H1. Public-sector unions to engage more in various protest actions than would privatesector unions.
The few existing studies of sectoral differences in labour conflicts note that strikes in the public sector are sometimes combined with large demonstrations (Vandaele, 2016), and research on nurses' resistance to public-sector reforms indicates that they strategically combine different repertoires of contention (Briskin, 2012). One reason for this is the public sector's dependence on public support for budget increases, and ultimately for increased pay for welfare-state workers (e.g. nurses, doctors and teachers). Therefore, some argue, public-sector unions are particularly keen to have public support before striking. Studies demonstrate that such support is secured through different forms of protest. Linderoth (2020) demonstrated that the Municipal Workers' Union in Sweden managed to secure public support for a strike in 2003 by using a diverse repertoire of protests, and Naughton (2022) showed how nurses in Ireland used public campaigns to mobilise the public in favour of a strike in 2019. While unions in both sectors could gain from having broader public support due to the importance of electoral and consumer behaviour, citizens are more affected by work stoppages in the public sector's welfare-state occupations (e.g. nurses, doctors and teachers). Thus, we expect: H2. Public-sector unions to combine strikes with other forms of protest actions more frequently than would private-sector unions.
Finally, the mobilisation of strikes, and of protests in general, is greatly dependent on unions' resources and opportunity structures for mobilisation (Tarrow, 1993a). Following economic globalisation, a profound restructuring of industry occurred in the 1990s (Gallego and Kurer, 2022). This trend and the spread of neoliberal ideas are the main reasons for unions' loss of power. Union membership has dropped across Europe. According to the power resource theory (Korpi, 1978), large membership constitutes a union's most critical power resource, so decreasing membership ought to affect the available repertoire of collective actions. In Sweden, working-class unions have shrunk significantly, and of them, private-sector unions have lost the most members (Jansson and Uba, 2019, pp. 86-87;Kjellberg, 2017). One reason for this is the shrinking industrial sector: while about 63% of employees belonged to the working class in 1985, this number had decreased to below 50% by 2015 (Ahrne et al., 2018). It is therefore unsurprising that the use of the traditional working-class protest actionstrikinghas steadily declined (Velden et al., 2007). Still, "declining conflict at work does not entail declining conflict about work" (Gall and Hebdon, 2008), and one mode of labour conflict Cycles of labour protests could have been replaced by another (Kelly, 2015). If there is some empirical evidence of such a replacement process, the declining number of strikes should be combined with increasing or at least constant levels of other union protest actions, such as demonstrations, rallies, petitions and protest letters. The increasing number of precarious workers, pressures of international market competition and shrinking membership (Bieler and Lindberg, 2011) have hindered strike mobilisation by private-sector unions. In this context, they might be more prone to opt for the less "costly" modes of protest. Evidence from other countries shows that unions have mobilised street protests to support the rights of precarious and migrant labour (Alberti and Per o, 2018;Paret, 2015). As global economic transformation and related labour market changes are more typical in the private than the public sector, we expect: H3. Private-sector unions to be more likely to replace strikes with other modes of protest than would public-sector unions.

Motivation for case selection
The three hypotheses about labour protesting in different economic sectors are tested using data from Sweden, a country usually described as having a coordinated market economy (Hall and Soskice, 2001). Like other Nordic countries, Sweden has a centralised bargaining system and a high degree of unionisation among public-and private-sector employees (70%, Medlingsinstitutet, 2021, p. 231). Swedish unions have experienced significant changes due to globalisation, but economic transformation, rationalisation and unemployment have affected the private and public sectors differently. While global competition has pressured wage formation and employment in the private sector, neoliberalism-related new public management reforms have often led to retrenchment and worsened working conditions in the public sector. We suggest that Sweden is an important illustrative case regarding labour protesting, even though high union density, strong corporate institutions and well-developed ties between the Social Democratic Party and the trade union movement would arguably make it a least likely case. While Swedish trade unions had other ways of gaining attention from and influencing politicians than street protests or strikes up to the 2000s (Gentile and Tarrow, 2009), the situation has changed. In the 1980s, union density was high, unemployment low, traditional corporate institutions were still intact, wage bargaining was centralised and the Social Democratic Party, a close ally of the union movement, was strong and in government in Sweden (it governed from 1982 to 1991). In the 1990s, Sweden underwent a serious economic crisis marked by high unemployment (H akansson and Nilsson, 2019). Parts of the tripartite corporate institutions were dismantled and union density started to decline. After that, in the first two decades of the 21st century, the structure of the Swedish economy was transformed due to digitalisation and automation. Trade union membership decreased rapidly (Jansson and Uba, 2019, pp. 86-87;Kjellberg, 2017), and the Social Democratic Party lost many seats in parliament. Although the 2008 recession primarily hit the private export sector, the political instability and difficulties forming stable governments of the 2010s also affected the public sector. Despite a slight increase in union membership during the Covid-19 pandemic, publicand private-sector unions are far from their membership numbers of the 1980s.
Furthermore, if we find empirical evidence of unions' use of the social movement action repertoire and differences across sectors in Sweden, similar tendencies might also be present in other Nordic countries. Considering that previous studies of labour protests have primarily focused on Southern Europe (i.e. Italy, Spain and Greece), the UK, or the USA, our analysis advances our understanding of labour protests in organised corporatism regimes. In addition, the relatively clear public/private-sector distinction among Swedish unions makes the comparison across sectors practically feasible. The availability of long-term data provides a unique opportunity to discuss the cycles of labour protests, rather than just covering the relatively short periods of peak protest at times of crisis.

Research design and methods
The analysis uses two kinds of data: protest event data and official strike statistics. The first are taken from the Swedish Protest Database (SPD) and described in detail in Appendix 1. SPD is a typical protest event dataset (see Hutter, 2014) based on news reporting in Swedish newspapers and newswires and covering the 1980-2020 period. We define protests as collective actions in which three or more individuals collectively express a grievance or make a claim for collective outcomes (e.g. demand labour law change or express solidarity with workers in another country). A coded event refers to a specific form of action (e.g. demonstration, strike or protest letter) reported in a particular geographical location (e.g. city or community). If two different organisations (e.g. unions) present a petition in the exact same geographical location on the same day, this is considered two events. However, newspapers sometimes do not specify the site and simply report on "several protests"; such cases are coded as single events with the location specified as the "whole country". In general, we have likely underestimated the total number of protests.
The SPD includes information about events ranging from common strategies such as writing to newspapers ("letters to the editor") to classical contentious actions such as petitions, demonstrations, strikes, acts of civil disobedience and violent attacks [1]. This study focuses only on protests mobilised by Swedish trade unions or by employees (e.g. workers, service personnel, bureaucrats, teachers and medical personnel), whom we can assume are unionised in Sweden. For example, we do not include farmers' protests, as they are represented by employers' organisations rather than trade unions. We do include all events by nurses or teachers, as they are very likely to be unionised. Although we do not include protests that incorporate some labour-related claims but were mobilised by other actors, for example, a political party demanding higher salaries or better working conditions, such protests form relatively small part of the excluded protests. We also exclude all Labour Day demonstrations (500 events) because these are recurring events and incomparable to other events.
We categorise the public-and private-sector protests in two steps. First, we determine whether the union mobilising the protest event organises members mainly in the public or the private sector. Welfare-state reforms and privatisations have blurred the distinction between the public and private sectors in Swedenfor example, teachers can work in either public of private schools. As classic public-sector domains such as education, healthcare and child and elderly care are still financed by the government, all unions in them have been categorised as public-sector unions. Several unions that organise members in both the public and private sectors have been coded as "both sectors". Among such unions are the Syndicalists, organising all employees regardless of occupation, and the Theatre Union, organising actors in both public and private theatres. Our categorisation differs from that proposed by, for example, Kjellberg (2020Kjellberg ( , p. 1041, which only considers police and military officers' unions to be public-sector unions. From the perspective of protest activism, we suggest that the primary funding source is more critical for organisations' opportunities to protest and their choice of protest strategies. Therefore, we opt for this categorisation (see list of unions in Appendix 2, Table A1). Second, as the media often do not report what union is behind a protest, we relate the professions mentioned to specific sectors. The term "worker" is usually used in the context of the private sector (e.g. industry or construction), while in the case of white-collar workers, we have tried to identify each profession separately. For example, engineers usually come from the private sector, while civil servants come from the public sector.
In total, our analysis considers 4,574 protest events, 46.5% of which were organised by the public sector, 46% by the private sector and 7.5% by mixed unions [2]. The primary strategies of these labour protests, which constitute about 48% of the examined actions, Cycles of labour protests are non-confrontational actions such as letters to the editor and opinion pieces (op-eds usually have a prominent position in Swedish newspapers). Strikes are the second most used strategy (17% of examined actions), followed by demonstrations (14%), petitions (7%), blockades or boycotts (4%) [3] and legal actions (3%). The remaining 7% constitute a diverse set of actions, including symbolic displays, threats of resignation and civil disobedience. The typical issues raised by these actions refer to: traditional labour claims (e.g. salaries, working conditions and collective agreement demands) (43%); problems specifically in the educational sector (13%) or healthcare sector (10%); democracy, solidarity and civil rights (10%); welfare retrenchment, austerity and privatisation (6%); unemployment (1%); public investments (2%); environment and energy (1.5%); and EU membership (0.6%) and other issues. While some of these claims are public sector specific (e.g. education and healthcare), there is no systematic and significant division between our protest data's private-and public-sector demands.
It is well known that protest event datasets suffer from media selection and representation biases (Ortiz et al., 2005), with smaller events in rural regions often being underestimated and the numbers of participants often being imprecise. We therefore complement the protest event data with official strike statistics. The Swedish Arbitration/Mediation Office provides information about the number of strikes in general and the working days lost due to strikes by sector for the entire studied period.

Protests in public and private sectors
The first step of the empirical analysis is to compare the cycles of protest mobilised by unions in the public and private sectors over 40 years. According to our first hypothesis, trade unions in the public sector should mobilise more protests, strikes and other forms of collective action than do unions in the private sector (H1). Figure 1 presents official strike statistics, which ER indicate a significant decline in the number of strikes (right axis) since 1991, confirming the results of prior studies of industrial action in Sweden (Th€ ornqvist, 2007). From a 100 per year in the 1980s, the number of strikes has dropped to 25 or fewer since the 1990s. Still, a clear difference between the private and public sectors is evident in working days lost (left axis in Figure 1). In the 1980s, the private sector lost, on average, 505,000 working days per year due to strikes, whereas the public sector lost only 212,000 working days per year. The situation reversed in the 1990s and 2000s, when the public sector lost significantly more days due to strikes than did the private sector. However, over the ten years from 2010 to 2020, once again, slightly more days were lost due to strikes in the private sector.
The opportunity structure for striking, determined by legislation regulating the right to strike, did not change significantly between the 1980s and 1990s (Ericson and Eriksson, 2020), so this cannot explain the extreme drop in the number of strikes. However, due to the economic crisis in the early 1990s, the Swedish government appointed the so-called Rehnberg Commission to coordinate all collective bargaining in almost all sectors in Sweden (Larsson, 2006). This temporary government intervention could explain the rapid drop in the number of strikes from 1990 to 1993, but not the new overall trend. It is also noteworthy that the Great Recession of 2008-2010 did not significantly increase the number of strikes. One possible explanation is the Swedish legislation on strikes: since most unions had signed three-year collective agreements in 2007, they had few legal opportunities to strike before 2010.
While strike statistics help describe industrial relations trends, they say little about other forms of contentious actions. To test our hypotheses properly, we must therefore look at the broader protest repertoires than just strikes. Figure 2 shows that the number of protests mobilised by public-and private-sector trade unions has not declined at the same rate as has the number of strikes. There are four distinctive peaks in the number of protests: in 1985, concerning conflicts over educational policy; in 1993, concerning comprehensive cutbacks in social insurance; in 2002, concerning dissatisfaction among welfare-state employees, also the rationale for a major strike in 2003; and in 2011, concerning conflicts over education and  , 1980-2020 Cycles of labour protests healthcare. Protests mobilised by unions organising employees in both sectors, follow the same general pattern of mobilisation. Two factors can explain this pattern: first, many of these protests are mobilised by the syndicalist union that organise employees in all sectors; second, many of these protests are different kinds of solidarity actions. Figure 3 presents the intensity of these protests, i.e. the equivalent of working days lost, calculated by multiplying the number of participants by the duration of each protest event (in days). The intensity is driven by large petitionscoded as lasting one day, but sometimes having over 500,000 signatures (e.g. LO mobilised a petition against cutbacks in sickness insurance in 1992). The 1996 peak is attributable to the many petitions that year, most concerning healthcare issues.
Altogether, when we do not take account of strikes and blockades, private-sector unions mobilised 41% and public-sector unions mobilised 52% of the examined protests, leaving 7% mobilised by mixed-sector unions. The evidence therefore supports our first hypothesis: public-sector unions protest more frequently than do private-sector ones, and the trend holds over time, although the difference between the sectors is not as clear when we consider the intensity of the protests. Figure 2 also helps test H3, i.e. that private-sector unions compensate for the decreasing number of strikes by increasing the number of protests of other forms. The number of protests (excluding strikes and blockades) has not increased since the early 1990s, and there is no difference between the sectors. Instead, all forms of protest events mobilised by Swedish private-sector unions have decreased slightly over time (see also Figure A1 in Appendix 2). Our analysis, therefore, does not provide clear evidence of the replacement hypothesis when examining the private sector. However, when analysing public-sector unions' strikes and protests, we find that, while the strikes have decreased in number over time, public-sector unions have not reduced the number of other forms of protest. Instead, public-sector unions' contentious actions increased up to 2011, indicating that other forms of activities (e.g. petitions or rallies) have replaced strikes. The intensity of protests excluding strikes and boycotts across sectors, 1980-2020 ER A better picture of the replacement trend is given by Figure 4, which presents the proportion of different protest strategies mobilised in the public and private sectors and suggests that the proportion of "other" strategies (e.g. demonstrations and symbolic actions) than the most demanding (i.e. strikes) or least demanding (i.e. letters or petitions) has increased over time. A few interesting trends are evident. First, as one would expect, public-sector unions rely heavily on influencing public opinion via letters and petitions, whereas private-sector unions used this strategy much less until 2011; after 2012, there is no statistical difference in the proportions of letters used by the public, private and mixed-sector unions ( Figure A2). As noted above, this change in trend might be related to the modified data collection strategy rather than to any significant changes in opportunities, grievances or resources for labour protest. Second, there is a clear trend that strikes form a continuously smaller proportion of protests mobilised by both public-and private-sector unions ( Figure A3). For the publicsector unions, there is a statistically significant increase in the proportion of demonstrations from 1980 to 1989 to 2012-2020. This suggests that while strikes declined in number, they have been replaced by demonstrations and other more demanding forms of action than letters and petitions ( Figure A4). The trend is not very robust, however, as the years 1990-2011 do not show any significant increase in demonstrations even though the proportion of strikes in the public sector decreased.
Finally, H2 proposed that public-sector unions combine strikes with other forms of protest because their success often depends on public support (Linderoth, 2020). Our data show that strikes are rarely combined with other forms of protest: only 9% of the examined publicsector protest events indicate a multiple-repertoire strategy, whereas the corresponding figure for the private-sector events is even lower. These numbers do not mean that unions do not combine strikes and other forms of action; instead, trade union activists probably make a strategic calculation before opting for combined protest tactics. For instance, in 1995, the public-sector unions for nurses and assistant nurses went on strike, combining this with a diverse repertoire of other protest actions to mobilise the public to oppose healthcare-sector cutbacks. Similarly, the Municipal Workers' Union merged a significant strike with Cycles of labour protests demonstrations and letters in the media in 2003. Similar campaigns can also be found in the private sector: for example, the Construction Workers' Union combined strikes, blockades, demonstrations and letters when protesting wage dumping and demanding collective agreements for migrant workers in 2005.

Conclusions
Although labour protests have attracted scholarly attention in the past, capturing an overview of the long-term cycles of labour protest across the public and private sectors has been neglected by researchers. Our study of Swedish trade unions' use of different collective action repertoires gives us insights into labour protests within a corporatist industrial relations regime. While we lack comparable data for other countries, it is clear that unions in Sweden are relatively active in using a broader protest repertoire than simply strikes, which are declining in number. In different regimes, where unions have fewer channels by which to influence politics, the protest rates are probably higher. Still, it is noteworthy that the number of protests, mainly strikes, was exceptionally high in the 1980s when Sweden experienced low unemployment, social insurance was generous and corporatist institutions were strong. With globalisation, declining union membership rates, and a trend towards increasingly dismantling the welfare state, strikes declined in number, a trend confirmed in other European countries. Protest mobilisation in general by Swedish unions has also declined, but public-sector unions have increased their share of such protests, whereas private-sector unions have clearly decreased their contentious actions over time. This indicates the growing vulnerability of these unions due to the increasing pressures of globalisation.
Our analysis demonstrates that unions in the public and private sectors still mobilise significant protests, and that these form certain cycles. Over time, however, there has been an overall downward trend in such action. This picture could indicate the difficulties of mobilisation even in the context of the high union membership rate found in Sweden. We find little evidence that public-sector unions systematically combine strikes with other forms of protest, though they do so occasionally. Raising public awareness of salaries/wages and working conditions via petitions and letters to the editor is a consistent strategy of Swedish public-sector unions. Future studies could examine whether this trend is declining with increasing digitalisation and how it compares with the situation in other countries. The numbers of letters to the editor and of petitions reported in newspaper articles have declined with increasing use of the internet, especially social media platforms, and traditional ways of measuring protest events will overlook such actions. This does not mean that unions no longer engage in such actions, but that they might have changed their precise means of protesting.
In his 2015 study, John Kelly suggested that strikes would gradually be replaced by other forms of contentious action. Our long-term analysis of 40 years of Swedish trade union protests only partly confirms this hypothesis, as we find the trend in the public but not the private sector. Considering that this expected replacement could be significant for the revitalisation of the trade union movement, this does not bode well for private-sector unions. On the other hand, our study of broadening the labour protest repertoire does not consider other means of revitalisation, such as transnational cooperation. In a context in which countries, including Sweden, are trying to limit the opportunities for striking, increasing the use of other forms of protest and engaging in international solidarity would likely benefit the entire labour movement.
Notes 1. The three-participant rule is not followed if the letter is signed on behalf of an organisation (e.g. the letter is signed by the spokesperson of a union).
2. These protest events represent about 30% of all protest events included in the SPD. ER 3. Gentile and Tarrow (2009) defined a blockade as a type of labour action regarded as a recognised means of industrial conflict in Sweden. Although such actions are far less costly than strikes, we acknowledge their character as a traditional labour action and therefore neglect boycotts or blockades when analysing time trends.  Katrin Uba is an Associate Professor at the Department of Government, Uppsala University. Her research focuses on labour movement mobilisation, political outcomes of environmental protests and climate strikes, as well as youth political activism.
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