Choosing to Work Part-Time – Combinations of Motives and the Role of Preferences and Constraints

Eight groups of part-time


Introduction
There is a shortage of workers in the public sector that will only increase in a near future.At the same time, the sector has a large percent of part-time workers and is very female dominated (Drange and Egeland, 2014).The lower salaries and pensions due to part-time work reinforces economic inequality between genders (Lanninger and Sundström, 2014).Therefore, it is important to study motives for parttime work in the municipal sector to better understand how the labour supply of those already working in the sector could be augmented, while also contributing to enhanced economic gender equality.
Part-time work can be divided into involuntary parttime work (those who cannot get full-time employment) and voluntary part-time work (those who have chosen not to work full-time) (Isusi and Corral, 2004;Kjeldstad and Nymoen, 2012).However, the extent to which voluntary part-time work really is voluntary has been debated (McRae, 2003).This article aims to contribute to an understanding of motives for part-time work and discuss how preferences and constraints influence decisions to work part-time, in a case study where the scope for preferences is great.The case involves employees with full-time employment who utilized an extended right to work part-time (working 50-90% of full-time).The context is Sweden, where discrimination of part-time workers is forbidden by law and where public child care makes full-time work possible for parents with small children.
In the European Union (EU-28), approximately 20% of the workforce work part-time.But part-time work is significantly more common among women than men, with 30% of all women and 10% of all men working parttime (Eurostat, 2017).Therefore, part-time work has been discussed as a gendered issue and understood as a solution allowing women to combine work with caring for children (e.g.Duncan et al., 2003;Hakim, 2002;McRae, 2003).The gendered prevalence of part-time work has also been explained by the organization, and culture, of femaledominated occupations (e.g.Abrahamsen, 2009) and as a strategy to avoid sick leave due to demanding working conditions (e.g.Drange and Egeland, 2014;Lanninger and Sundström, 2014).The decision to work part-time has also been explained in more positive terms as a strategy to gain more influence over one's own everyday life priorities and time-use (e.g.Larsson and Björk, 2017;Hörning, Gerhard and Michailow, 1995).However, these explanations have seldom been discussed in relation to each other (Jamieson et al., 2007).
In previous research, there has been a heated debate regarding the relative importance of women's own preferences for part-time work and structural constraints hindering their access to full-time work (Crompton and Lyonette, 2005;Gash, 2008;Hakim, 2002;Yerkes, 2013).Those who maintain the importance of constraints draw attention to both the lack of available child care and the high price of part-time work in terms of lost income, career opportunities, and pension savings.Even though the conditions for part-time work differ between

Previous Research
Previous research has found that preferences for part-time work are highly influenced by the part-time or full-time work norms of the national context (Wielers, Münderlein and Koster, 2013).Generally the full-time work norm is strong in the Swedish labour market.Sickness benefit, parental leave benefit, unemployment benefit, and retirement pensions are all income based and thus stimulate full-time work (Junestav, 2004).Yet in Sweden 13% and 34% of employed men and women, respectively, have part-time contracts (Eurostat, 2017).Choices to work part-time are highly influenced by the type of occupation and the sector, where for example part-time contracts are prevalent in the care sector (Abrahamsen, 2009;Nicolaisen and Bråthen, 2012).At female-dominated workplaces, there may even be a local part-time culture.As a consequence of full-time work norms, women's parttime work has been problematized, but also in relation to gender-equality ideals where part-time work is considered detrimental for women's income and career opportunities (Hirdman, 1990).
The importance of primarily women's own preferences and priorities in relation to work, family, and leisure activities has been discussed for decades.Giddens (1992) argued that the family is undergoing a democratization process that is giving women more opportunities to negotiate commitments within the family and at work.Hakim (2002) even argued that women's part-time work by now is a result of their preferences.Others claim that prioritizations between family and work are still shaped by gendered moral rationalities (Ahlberg, Roman and Duncan, 2008).Thus, structural constraints would have a greater impact than preferences (see e.g.Crompton and Lyonette, 2005;Duncan et al., 2003;Yerkes, 2013).
Part-time work can also be an individual coping strategy when work is found to be too demanding (Drange and Egeland, 2014).This strategy is more common in femaledominated occupations (Nicolaisen and Bråthen, 2012).Due to new public management strategies and raised productivity expectations in municipalities in Sweden, many workers have witnessed an increase in workload as a result of fewer staff, shorter times to perform tasks, more care recipients to attend to, and so on.This has in turn led to emotional strain as workers experience that they can no longer satisfy the needs they perceive (Björk, Björnberg and Ekbrand, 2013;Forsberg Kankkunen and Bejerot, 2017;Trydegård, 2012).Previous research has also found that among women in the Nordic countries, ill health is an important motivation for part-time work (Lanninger and Sundström, 2014).
Depending on available public and private care solutions, having care responsibilities for ageing relatives can also be a motive for working part-time (Le Bihan et al, 2013).Although in Sweden the responsibility for care of the elderly rests with the municipality and not with the family, recent decades have seen a decrease in the services offered and, in practice, families are shouldering a greater share of the responsibility for the elderly.To some extent this has effects on caregivers, mainly women's, working hours (Ulmanen and Szebehely, 2015).
There are also studies of preferences for part-time work, where part-time is found to be strategy to get more time and autonomy while down-prioritizing material and career ambitions (Larsson and Björk, 2017;Hörning et al., 1995).In a Danish study, Lind and Rasmussen (2008) even describe a change in part-time work patterns where women's part-time work has decreased, while part-time work among those under the age of 25 has increased.Part-time work is then becoming less of a trap for women and more of a positive opportunity for young people to temporarily combine work and education.Danish parttime workers are also generally satisfied with working part-time (Wehner, Johansen and Navrbjerg, 2002).
Even though the debate regarding the relevance of preferences in part-time work has mainly concerned mothers' part-time work, the question is also relevant for part-time work in a broader sense.To what extent can part-time work be understood as a result of preferences and what is the relevance of different constraints?Constraints may be normative, thus shaping expectations, identities, and ideals; or more concrete, such as a lack of access to full-time jobs or child care, or health issues (McRae, 2003).Thus, a distinction can be made between more unconstrained preferences and accommodated preferences, or between part-time work due to preferences for more free time versus part-time work due to the difficulty of achieving a life balance when working fulltime (Gash, 2008).In the present study we cluster parttime workers based on their motives for part-time work.To be able to discuss the emphasis on preferences and on accommodation to constraints for each cluster, we analyze how combinations of motives are connected to sociodemographic factors and the workers' future working time plans and potential reasons to work full-time.

The case
The case studied in this article is part-time work by employees of the municipality City of Gothenburg, Sweden.In Sweden the welfare system provides affordable access to public child care and public eldercare (Björk, Björnberg and Ekbrand, 2013).It is forbidden by law to discriminate against part-time workers, and part-time workers have equal access to medical services, because these are publicly funded.Workers have legal rights to work part-time when studying and when they have children below the age of eight (Swedish Code of Statutes, 1995:584;1974:981).These conditions are sometimes referred to as high-quality part-time work (Drange and Egeland, 2014).
It has to be noted that part-time work in Sweden, and in the case of this study, often implies long hours in comparison to many countries outside the Nordic context.In the City of Gothenburg, the average working hours of part-timers are 32 hours (40 hours is full-time in Sweden), which is above the OECD definition in which part-time work is less than 30 hours per week (Bastelaer, Lemaitre and Marianna, 1997).
The Swedish municipal sector has been criticized for its heavy use of part-time contracts, giving their employees, mainly women, a lower income and pension savings.Therefore, in recent years, the City of Gothenburg has decided to offer all employees full-time contracts.However, many employees wanted to continue working part-time, so the City offered full-time contracts with an extended right to work part-time.The policy stipulates that line managers are not permitted to decline such a request without first trying to find a solution with the aid of the central HR department (City of Gothenburg, 2015).

Dataset
A survey was conducted in 2016 among part-time working employees of the City of Gothenburg.Each respondent was given written information about the purpose of the study and how the information would be handled.They consented to participate through the survey.The City has about 50,000 employees, and the sample was identified with the aid of the central HR department and consisted of those who had full-time contracts but had opted to work part-time.Employees who had worked part-time for more than 10 years were excluded from the sample, as well as those who had exercised their legal right to work parttime for studies and those who were receiving parental leave benefits.This resulted in 3331 individuals, and our analysis is based on a survey and employment records data.In total 994 respondents completed the web-based survey (30% response rate).A non-response analysis that included age, gender, the extent of part-time work, and the Swedish Socio-Economic Index (SEI) 1 showed that it was only the distribution of SEI class that differed between respondents and non-respondents.Therefore, when describing the clusters (see below) a weighting factor has been used to compensate for the underrepresentation of manual workers.

Operationalization
The motives for part-time work included in this study are based on data from Eurostat and Statistics Sweden, as well as previous research (Hörning et al., 1995;Isusi and Corral, 2004;Jamieson et al., 2007;Lanninger and Sundström, 2014;Statistics Sweden, 2012a) volunteer work, political engagement).The format of the survey questions was 'How important were the following reasons for you when you made the decision to shorten your working hours?' with responses ranging from 1 not important at all to 5 very important.Thus, the questions allow for combinations of motives as well as ratings of the relative importance of different motives (cf.Van Rijswijk et al., 2004).Four out of the ten motive items were strongly correlated pairwise: Other part-time work and Starting or running own business (r = 0.52); and Full-time work is too physically demanding and Full-time work is too mentally demanding, (r = 0.61).To manage this, the four variables were merged into two (controlling for Cronbach alpha, which was 0.68 and 0.78, respectively) (Sambandam, 2003).In the merged variables, each respondent has been given the higher of the two values.The reason is that the merged variable should illustrate if the respondent either has mentally demanding work or physically demanding work.This way, the merged variable, Full-time work is too demanding, does not underestimate the importance of any motive.There was a relatively large percentage of missing values in our main dependent variables.Even though 985 respondents answered the question concerning motives for part-time work, only 752 assessed the importance of all ten motives.The missing values were found to be missing at random (MAR).Thus, we used the expectation maximization (EM) procedure to infer the missing data as recommended by, for example, Hair et al. (2010).The EM procedure tends to underestimate standard errors while overestimating the significance levels of tested differences.However, since this study was exploratory, it was preferable to adopt a liberal rather than a conservative approach to significance testing (Acock, 2005).
To understand the relevance of accommodation of preferences to constraints we also analyze sociodemographic factors shown in previous research to affect constraints.Educational level, socio-economic status, and type of occupation are interconnected and can influence motives for part-time work.They affect the availability of economic resources, the ability to get another job, and working conditions (Bihagen and Halleröd, 2000).Education was operationalized through the survey question 'What is your level of education?' 2 Socio-economic classification was based on the registered type of work and position classified according to the Swedish Socio-Economic Index (SEI) (Statistics Sweden, 2017).The registered type of work was also classified into care jobs 3 and other jobs.Care professions are characterized by demanding working conditions, both in terms of physical strain and emotional demands (AFA Insurance, 2015; Dellve, Lagerström, and Hagberg, 2003).Both the share that state that their job is physically demanding and mentally demanding is twice as high among care workers as in the work force in general (Statistics Sweden, 2019).As mentioned above, health also affects part-time work choices (Lanninger and Sundström, 2014).Health was operationalized by asking respondents about their work-related physical health: 'How often do you experience physical pain (e.g. in head, back or arm) that you associate with your working environment?' 4 Work-time schedules are relevant because atypical working hours can be demanding, in particular in relation to combining work and care commitments (Le Bihan, Martin, and Knijn, 2013).Worktime schedules were operationalized through the survey question 'When do you work?' with the alternatives only during the daytime on weekdays and evenings, nights, weekends, or a combination of daytime on weekdays and other times.We also include total working hours, based on the City's registered information.Age, from the registered information, is relevant for our analysis in order to understand both stage in life and in relation to health.Finally, as discussed above, gender and having young children are very relevant factors in the choice to work part-time (Crompton and Lyonette, 2005;Duncan et al., 2003;Yerkes, 2013).Having young children was measured through the survey questions 'Do you have children living with you at home?' and 'How old is your youngest child?' Gender was based on the City's register of their employees' social security numbers.
To better understand the level of accommodation of preferences to constraints for part-time work, respondents' future plans and understanding of available alternatives were of interest.Thus, the respondents were asked: 'What are your thoughts on your working hours in the future?'The response alternatives were: I see part-time work as a temporary solution and I will start working full time when it is possible and I see part-time work as a long-term solution and I intend to continue with it if possible.They were also asked what would make them choose full-time work again.The response alternatives were: The children get older and manage more by themselves; The adult family member I care for no longer needs my help; My health gets better; Reduced workload; e.g. through hiring more staff; I need a higher income; I reduce my volunteer commitments; Nothing would make me work full-time; and Other reasons.

Cluster analysis
To study how part-time workers can be categorized based on their motives for working part-time, a cluster analysis approach is appropriate.The idea of cluster analysis is 'the classification of data as suggested by natural groupings of the data themselves' (Hair et al., 2010: 508).In practice, cluster analysis forms groups (i.e.clusters) of homogenous respondents based on a number of predetermined variables.The different clusters of respondents should be as heterogeneous as possible.Using a hierarchical method, based on a log-likelihood distance measure with the distance between two clusters defined as the decrease in log likelihood if the two clusters were combined into a single cluster, more and more clusters are formed that gradually become more internally homogeneous.The aim is to find a solution with as few clusters as possible that remain homogenous and possible to explain theoretically.A two-step clustering procedure, available in SPSS (release 24.0), was used to cluster the 984 part-time workers who had reported motives for their part-time work.

Comparing the clusters
A description of each cluster and comparisons of clusters regarding motives and sociodemographic factors can be found in the next section.T-tests were performed to identify statistically significant differences between clusters. 5We thus assess the relative importance of motives for each cluster compared to the other clusters.The analysis focuses on combinations of motives for each cluster to discuss the relevance of preferences and accommodation to constraints.For example the motive 'more own time' can expresses a preference for deciding over one's own time, it can also be a manifestation of a need for recovery due to the experience of pressure from working life or private life.Thus, each motive can be understood differently depending on how it is combined with other motives.
In order to obtain a qualitative description of the different clusters, open text answers from the survey were analysed.These qualitative examples added to the description and validation of the clusters, and are aligned with the exploratory nature of this study.The qualitative analysis also gave indications of the relevance of preferences and accommodation to constraints in different motives.

Results and Discussion
The mean age of the part-time workers 6 in the study, 48 years, is just slightly older than the average employee in the City, 46 years.Women are over-represented among parttime workers: 86% compared to 78% for the City as a whole.Only 26% of part-time workers have young children, and 53% of the respondents reported that they had a university degree, which is twice as high as the Swedish labor force on average (Statistics Sweden, 2018).Of these part-time workers, 63% work in ' care jobs' such as preschool teachers and nurses in eldercare.41% of the part-timers work on weekends or evenings, or nights (Table 3).
A two-step clustering procedure was used to cluster the 984 part-time workers based on their motives for part-time work.The algorithm calculates the Bayesian Information Criterion (BIC) for a variety of clustering solutions and uses this value to find an initial estimate of the optimal number of clusters.Table 1 shows the results of this procedure for solutions with 1-15 clusters.The BIC value declined gradually up to the eight-cluster solution and then increased for nine-cluster and higher order cluster solutions.Low BIC values are desirable, suggesting that the eight-cluster solution is optimal.However, the SPSS algorithm chose the seven-cluster solution as optimal, using the large decline in the BIC value and the high ratio of distance measures (SPSS Corporation, 2001).Yet the eight-cluster solution was preferred, since it divides the cluster valuing the motive of 'more time with children' as the most important into two clusters; one which only values 'more time with children' and one which also values 'full-time work is too demanding', 'managing all household work', and 'more own time' (see Table 2).
Table 2 shows the clusters and the average importance that the respondents in each cluster gave to each motive.The motives for part-time work are complex for most of the clusters and part-time workers stated on average 2.5 motives as important (value four or five) for their parttime work, but the number of important motives varied between clusters.Generally, the two most important motives for starting to work part-time were 'full-time is too demanding' and 'more own time'.This may be related to the large proportion working in care occupations and having atypical working hours (cf.Dellve et al., 2003).However, almost all parents with children under the age of eight rated the motive 'more time with children' as very important.'Managing all household work' was also often rated as important.Finally, the last four motives in Table 2 were important to relatively few respondents.
Naming the clusters formed part of the analysis and the names are based on one or several motives that the respondents in the cluster rated highly compared to the other clusters.Five clusters were simply named based on one motive that they rated especially highly: Demanding jobs, Caring for adult family member, Community engagement, Studying, and Two jobs.Two clusters reported high values for the motive 'having more time with children'.One of them had this as their sole motive and was named Solely caring for children.The other cluster also gave high importance to motives indicating that they experience everyday life as demanding, thus the cluster was named Caring for children.Demanding lives.Finally, one cluster found full-time work too demanding, but also needed time to manage all household work, and wanted more own time.The cluster was named Demanding lives.
In the section below, the results in Table 2 are analyzed together with Tables 3 and 4. We have grouped the clusters based on their patterns of motives and discuss our results in relation to previous research.To get a more nuanced sense of their situation, quotes from their comments provided in the survey 8 are analyzed.

Two clusters caring for children
There are two clusters where most of the respondents are parents with children under 8 years of age, Cluster A (5%): Solely caring for children and Cluster B (18%): Caring for children.Demanding lives.These two clusters have the lowest average age, about 40 years, and more often than the other clusters they have a university degree and white collar jobs at a high level (Table 3).Also in previous research high-level white collar workers are overrepresented among those working part-time to gain more time with their children (Larsson, 2017).This may be due to ideals of involved parenthood being more influential in this group, who therefore may prefer to prioritize shorter days for their children in preschool (Bergold, Vedin, and Lorentzi, 2017;Forsberg, 2009) and that high-level white collar workers can more easily afford to work part-time due to their higher incomes.
In many countries, part-time work among mothers is motivated by the lack of good quality, affordable childcare (Kimmel, 2006).However, this is usually not the case in Sweden (Björk, Björnberg, and Ekbrand, 2013) and was not at all mentioned in the comments provided by respondents in this study.Instead part-time work among parents seems to be motivated by a desire to spend more time with their children and for a less hectic family life.
The main difference between the two clusters of parents is in the number of reasons they state for working parttime.While the cluster Solely caring for children almost exclusively give high value to the motive to have more time with their children, the cluster Caring for children,  Caring for adult family member (e.g.parent, partner, or adult child) Other part-time work/starting or running own business Community engagement (e.g.sports coach, volunteer work, political engagement) The question was 'How important were the following reasons for you when you made the decision to shorten your working hours?' 1 equals 'not important at all' and 5 equals 'Very important'.The figures show mean values of each motive for each cluster group.
A letter in a cell means that the average for this cluster is significantly higher than another cluster, the letter specifies which this other cluster is.Significance level: 0.05.A letter in a cell means that the average for this cluster is significantly higher than another cluster, the letter specifies which this other cluster is.Significance level: 0.05.I. Including children's nurses, preschool teachers, physical and rehabilitation assistants, personal assistants, registered nurses, assistant nurses, hospital orderlies, student support staff, addiction treatment assistants.
II.The alternatives were 6 = every day, 5 = a couple of days per week, 4 = once per week, 3 = a couple of days per month, 2 = more seldom 1 = never.III.Based on the Swedish Socio-Economic Index (SEI) (Statistics Sweden, 2017).
demanding lives also valued the motive 'managing all household work'.In addition, this cluster attach more importance to the motive 'full-time work is too demanding, physically or mentally' and 'more own time' which can be interpreted as a consequence of experiencing some extent of pressure from both working and private lives (Table 2).
One aspect that reinforces the differences is that a larger share in the latter cluster found that their workload would need to be reduced for them to be able to return to fulltime work (Table 4).
Typical comments from the first cluster stressed the importance of spending time with their children: 'Before I had children, I worked full-time.Since then [I've worked] part-time, except for when my husband was on parental leave.';'I want to be more involved in my children's upbringing and enjoy the time when they are young.'The latter cluster gave similar comments but also stressed their work situation and private life: 'Working part-time mainly because of children and family.But I wish I could continue working part-time to have more time for something else.However, I am worried that it will affect my retirement income.';'I cannot cope with working full-time.When you work shifts and every other weekend.[…] As a part-time worker you have more opportunities to recover.' Part-time work among the latter cluster therefore appeared to be more of an accommodation of preferences to constraints due to the pressure they were experiencing.The high importance of 'more own time' and the comments regarding 'time for something else' do however also indicate a preference to prioritize free time.
There may, however, also be normative constraints affecting parents' preferences.Although the gender distribution in the clusters of parents did not differ from the gender distribution among part-time workers in the municipality as a whole, 86-87% of parents in the clusters are women.Therefore, norms concerning motherhood and the indispensability of a mother's presence (Elvin-Nowak and Thomsson, 2001) are relevant to understanding their choices to work part-time.Mothers also generally take greater responsibility for, and thus need to spend more time on, the care of their children (Statistics Sweden, 2012b).Fathers who do not work part-time may also be influenced by gendered norms of parenthood.Even though workplace acceptance of fathers' part-time work is generally higher in female-dominated workplaces (Larsson, 2012), part-time work is still not a normative way of being a father and the norms connecting fatherhood with breadwinning are still influential (Björk, 2013).

Four clusters with jobs that are too demanding
Compared with the clusters of parents, the four clusters Demanding jobs, Demanding lives, Caring for family member, and Community engagement all attached greater importance to the motives 'full-time work is too demanding' and 'more own time'.We understand these two motives to be linked because the motive 'more own time' included 'time for relaxing' as an example, and finding full-time work too demanding may imply a need for more time for rest and recuperation.While the motive 'more own time' can also be a preference for valuing other things in life than work, many of the text answers mentioned health problems, stress at work and lack of influence at work.
More than the other clusters, Cluster C (16%): Demanding jobs is solely motivated by finding full-time work too demanding and wanting more time for themselves (Table 2).The cluster has the highest proportion of respondents who answer that they could start working full-time 'When my health gets better', large proportions also answer 'When the workload is reduced' and that they do not think anything could make them work full-time (Table 4).The cluster has a relatively large proportion of men and the average age in this cluster is higher than in the clusters with parents (Table 3).Typical comments from this cluster stressed dissatisfaction with the work environment and the organization of work: 'Depending on the nature of the work, I could think of working fulltime if it's a 'good' job.At the moment, I don't have the energy.';'I have worked at several workplaces and it was bad management that caused my health problems.'Thus, part-time work for this cluster is mainly motivated by demanding work and health issues, factors that previous research has described in terms of the constraints (Drange and Egeland, 2014;Lanninger and Sundström, 2014).
Cluster D (20%): Demanding lives also, and to an even greater extent than the cluster Demanding jobs, attaches importance to the motives 'full-time work is too demanding' and 'more own time'.They claim 'managing all household work' to be an important motive to a higher degree than any other cluster (Table 2), even though very few of the respondents in the cluster have children under the age of eight (Table 3) and therefore do not have the extra household chores that small children entail.This combination of motives indicate that the respondents in the cluster experience both work and private life as demanding.This cluster have the lowest proportion of respondents with a university degree, the highest proportion of care workers, and the highest frequency of physical ailments (Table 3).The respondents in the cluster also most often stated that nothing could make them start working full-time again (Table 4).Typical comments from this cluster bore witness of heavy work and wavering health: 'This work is so demanding, physically and mentally, so I cannot work full-time!I cannot handle the stress.But when I was younger I had more energy!';'Part time is my way of coping without having to be on sick leave now and then.' Beside the motive that gave Cluster E (14%): Caring for family member its name, other important motives are that 'work is too demanding', and 'more own time' (Table 2).This cluster has a high proportion with care jobs and a relatively low proportion with a university degree (Table 3).Women are over-represented in this cluster (95%), which is in line with the gender distribution in responsibility for the care of older relatives described in previous research (Björk, 2017;Ulmanen and Szebehely, 2015).Typical quotes from this cluster emphasize their care responsibilities and a feeling of being at the end of their working life: 'My intention is to start working fulltime, but maybe I won't be able to cope even if my parents  The question was 'What would make you choose to work full time?'.One or several reasons could be stated.
The figures show percentage in each cluster that responded positively to each potential reason for starting to work full-time.
A letter in a cell means that the average for this cluster is significantly higher than another cluster, the letter specifies which this other cluster is.Significance level: 0.05.Categories with percentages equal to zero are not used in comparisons.
I. The proportion can be expected to be significantly higher than cluster A. The comparison is diffused by the proportion 0% in cluster A.
die before I retire.';'I have worked a GREAT DEAL of my life.TOO much I think now.' Previous research has shown that in Sweden part-time work is almost only chosen by family caregivers in intensive care arrangements, thus accommodating work-time preferences to the constraints of extensive care responsibilities (Ulmanen, 2015).Cluster F (8%): Community engagement is mainly characterized by the importance of the motive 'volunteering commitments (e.g.sports coach, volunteer work, or political engagement)'.This is not their most important motive, but it is what distinguishes them from other clusters.Respondents in this cluster on average reported a higher number of important motives than the other clusters, which can be interpreted as them having many good reasons to work less.Their other motives were (in descending order): 'more own time', 'full-time work is too demanding', and 'managing all household work' (Table 2).In this cluster, the proportion of men is the highest (24%), and the cluster has the highest share of respondents who work nights and weekends.Over 80% stated that they see part-time work as a long-term solution (Table 3) and a large proportion also stated that nothing would make them work full-time again (Table 4).
In the comments from this cluster, critique of the fulltime norm was expressed: 'Tired of being questioned by management and even unions about choosing to work part-time.The norm is that it is "wrong".Have been offered full-time work to be "rescued", which is patronizing.''Working part-time is a priority in life where I choose to value friends/community engagement over income from employment.'The cluster thus experienced pressure from their working conditions but they also seemed to be driven by preferences for engagement in other activities and, as described by previous research, prioritizing other values than work and money (Larsson and Björk, 2017;Hörning et al., 1995).
Many respondents in all these four clusters did not see their part-time work as a temporary solution, and many stated that they would work full-time again only if the workload was reduced or if their health improved (Table 3).As seen in previous research, part-time work can be a strategy to be able to keep on working all the way to retirement or to avoid taking sick leave (Drange and Egeland, 2014;Lanninger and Sundström, 2014).Even though the four clusters had complex motives, their working conditions seemed to be the main reason for working part time and it dominated the comments from respondents.
The opportunity to work part-time is a resource for employees to be able to take responsibility for their own health, but there are also other aspects of working hours that are important for employees' health and wellbeing, such as employee influence over schedules and the predictability of working hours (Swedish Government Official Report, 2002).In the comments, we found that many respondents who work in eldercare expressed powerlessness in relation to the lack of predictability of their working hours and, above all, the lack of influence over their schedules.In the absence of that, the number of weekly working hours was the only thing the employees could control.
Interestingly, we did not find any cluster of older parttime workers in white collar occupations.Either the group was too small to form a cluster, or experienced white collar workers might not be as motivated to work part-time.

Two clusters with full-time commitments
The last two clusters, Two Jobs and Studying, have wellestablished motives for working part-time.Interestingly, the respondents in these two clusters also attached importance to other motives.Their other part-time engagement was then part of a combination of motives, rather than their only motive, to work part-time.A quarter of Cluster G (10%): Studying have children under the age of eight (Table 3), and many stated that they intend to start working full-time when their children grow older.A large number also stated that they can start working fulltime only when the adult family member they care for no longer needs help (Table 4).Comments from this cluster also expressed a wish for continued part-time work after finishing studies.Other comments described part-time studies as a strategy to get respite from full-time work: 'Part time was part of a solution to supplement and develop my professional qualifications through studies, while at the same time getting a limited period of respite where I could gain some perspective on my work situation.' Cluster H (8%): Two jobs gives high ratings to either the motive ' other part-time work or project work' or 'starting or running own business '. 9This means that they have other working life obligations as the principal reason for reducing their working hours in their main job.But these respondents also rated the motives 'full-time work is too demanding' and 'more own time' highly (Table 2).This cluster has the highest share, 85%, of respondents who see part-time as a long-term solution (Table 3).Typical comments from this cluster either stated a high workload at their main job or a wish for fulfilment through other work: I hope to continue working part time as a teacher because it is too stressful working full-time as a teacher.The workload is way too high.But I hope to continue working with my own company the day of the week that I am free from school.
My part-time job gives me money for food and rent.It gives me relationships with colleagues … The rest of the time I work creatively in my own company, without having to worry about my financial situation.
In both these two clusters, respondents may have either a high level or a low level of accommodation of preferences to constraints.For those indicating a low degree of accommodation, there is a pull towards something they want to do, for example to study or to have a parallel job.For those indicating a high degree of accommodation, there is instead a push away from, for example, a demanding work situation.
The case studied, a municipality in Sweden granting employees full-time contracts with an extended right to work part-time, was expected to allow for a great role for preference in part-timers combinations of motives.Among the heterogeneous groups of part-time workers identified through the cluster analysis, some were indeed dominated by the positive motives of wanting to spend more time with one's children, on studies or on other part-time work.Yet the picture formed through our analysis is that in most of the combinations of motives that emerged, part-time work seemed to be perceived as a necessity or a coping strategy.For most of the clusters, working part-time functioned as an individual strategy to cope with ill health and/or work that was perceived to be too demanding.This might partially be explained by the case studied: a municipality with a high number of demanding care jobs and demanding jobs in schools (AFA Insurance, 2015;Statistics Sweden, 2019).Thus, parttime workers who were more motivated by preference are overshadowed by the large groups of employees with very demanding jobs in the empirical data.
It may also be that respondents were influenced by the full-time work norm when answering the survey, and thus felt an urge to have 'legitimate' motives not to work full-time.Stating that 'work is too demanding' might be perceived as more legitimate than just wanting 'more own time'.Yet, through our qualitative analysis of the text answers, we find support for interpreting these answers as indicators of constraining factors in the work environment and organization of work.
Working part-time to cope with a demanding work environment is problematic because the individual risks bearing the costs of detrimental working conditions.Liberal work life policies may reduce sick leave, but part of the reduction can be an informal sick leave paid by the employees.While the extended right to work part-time enables freedom of choice for employees, they might have been better served by adjustments of the workload, more flexibility and opportunities to influence working hours.Improved working conditions in the municipal sector are important for avoiding sick leave and enabling employees to work full-time and receive a full salary.

Conclusions
The findings contribute to our understanding of motives for part-time work for different groups of workers, and we have discussed the relevance of accommodations of preferences to constraints, also in a case where the scope for preferences is great.The survey design enabled a complex picture of combinations of motives to emerge, and the analysis show that part-time workers are not a homogenous group.Through discussing these groups and their combinations of motives in relation to previous research on preferences and accommodations to constraints, the study adds to a nuanced understanding of what motivates 'voluntary' part-time work.The diverse combinations of motives indicate varying degrees of accommodation of preferences among different groups of workers to constraints related to gender, age, family situation, and occupation.While previous research has focused on the availability of childcare and full-time jobs, we found that when these conditions are met, working conditions and workload were of great relevance in the choice to work part-time.Gendered moral rationalities were also relevant, because women were over-represented in clusters who reported their motives for working part-time as care of children or another close family member (see also Ahlberg, Roman, and Duncan, 2008).Thus structural constraints, such as gendered norms, working conditions, and being unable to adapt work to workers' capacities and health, probably have impacts on preferences for part-time work (see also Crompton and Lyonette, 2005).
This study was conducted on a specific case where there was great flexibility to choose both full-time and part-time work.Yet, other factors such as the availability of child care and the rights of part-time workers are fairly similar across all the Nordic countries (Drange and Egeland, 2014;Eydal and Rostgaard, 2011).Also with regard to workload, care workers in all Nordic countries have experienced a change for the worse in both working conditions and the opportunity to meet clients' needs due to new public management reorganizations and austerity policies (Trydegård, 2012).Thus, even though the availability of full-time work and the right to work part-time varies between countries and employers, our results are probably valid for 'voluntary' part-time work in the municipal sector in the Nordic countries.
As this study was cross-sectional, we were not able to study how working hours and workers' motives and preferences for part-time work changed over time and in response to changing life circumstances.Another weakness of the study was that the data did not enable a comparison between workers who claim the right to work part-time and the workers who do not.

Policy implications
Our results indicate that even though all respondents have the formal right to work full-time, not all of them are working part-time only as a result of preferences.What could increase the possibilities for those that might want to work full time?One answer, found in this study, was having a reduced workload, for example, more time for each home visit to help the elderly or more staff in school.This result indicates that work is not being organized sustainably for all employees.One step to tackle this problem would be to work more actively with job task management, where tasks are more transparent, devisable, and transferable (Ibanez, 2011).Another step is to increase public funding of municipalities.Workers also stated that they could start working full-time when their children got old enough to manage more on their own.Since women were over-represented among the clusters caring for children, policies at the workplace or national level to encourage fathers to work part-time might enhance the possibilities for mothers to increase their working hours.
Even though the extended right to work part-time risks individualizing the costs of detrimental working conditions, it also has advantages.The right to work part-time is likely to give employees the chance to keep on working, despite health problems, old age, and so on.If unable to work part-time, a proportion of these employees would not be working at all (Wadensjö, 2006).The extended right to work part-time also gives employees
I. The changes are from the previous number of clusters in the table.II.The ratios of distance measures are based on the current number of clusters in relation to the previous number of clusters.A high number indicates that the clusters are well separated.

Table 2 :
Cluster mean rating of motives for working part-time.

Table 3 :
Sociodemographic comparison of the clusters.

Table 4 :
Potential reasons to work full-time for each cluster.