Table 1: Definition of indicators for the multidimensional precarious employment construct in the 2010 EWCS
	Dimension	Indicator	Source indicator(s)	Categories
1	Employment instability Type and duration of employment contract, reflecting the degree of certainty of continuing work. Short contracts predispose workers to job insecurity.	Type of employment contract	What kind of employment contract do you have?	i) Permanent ii) Non-permanent
2	Low-income level This dimension reflects the receipt of material rewards, ie, monetary rewards (or income) and non-wage benefits. Relative income reflects wage income sufficiency at the household level to meet regular or unexpected expenses.	Country-specific relative income	Thinking of your household's total monthly income, is your household able to make ends meet?	i) Low household income meets needs easily ii) Low household income meets needs with difficulty
	Benefits in nature refers to additional benefits (eg, health insurance) in addition to the ‘monetary’ wage that are a typical feature of SER-employment, and characterise the most valuable core-employees	Benefits in nature	Thinking about your earnings from your main job, what do they include - Advantages of other nature?	i) Mentioned receiving ii) Not mention receiving
3	Lack of rights and social protection An important aspect of collective organization is the occupational health and safety of workers; insufficient information on these issues is reflective of problems in the communication between management and employees (Underhill and Quinlan 2011).a Workplace rights provide non-wage employment benefits (eg, holidays, sick leave, etc).	Information on health and safety	Regarding the health and safety risks related to performance of your job, how well informed would you say you are?	A binary indicator was created, where: i) Well informed ii) Not well informed
4	Incapacity to exercise rights Workers powerlessness to exercise their rights. It includes having to work on exceptional hours regularly (Sunday work and/or overtime work) and not receiving any compensation for these exceptional working times. It is viewed as an indication of low employment quality because the typical SER-employment should provide compensations for extra (non-standard) inputs. Possibly due to workers' lack knowledge of their rights and implicit or explicit threats of job loss or wage cuts. It is complementary to the previous dimension.	Uncompensated flexible working times	Computed from responses to a combination of questions: a) How many hours do you usually work per week in your main paid job? b) How many times a month do you work on Sundays? c) Thinking about your earnings from your main job, what do they include (extra payments for additional hours of work/overtime)? d) Thinking about your earnings from your main job, what do they include (extra payments compensating for Sunday work)?	For the analyses, we created a binary indicator, where: i) Compensated, ie, Doing overwork (>40 hrs a wk) and/or on Sunday, but compensated for it ii) Uncompensated/No flexible times, ie, Not doing overwork and/or Sunday work, or not being compensated for it.
5	Absence of collective bargaining/disempowerment This indicator refers to the way workers' employment conditions, eg, wages, and the setting of working hours, are negotiated (individualized versus collective bargaining). Company-determined working times set with no possibility for changes reflects the erosion of the power of organized labour and “employer-determined employment relations”, and are regarded as an expression of poor collective bargaining power of the workers.	Self-determination over schedule	How are your working time arrangements set?	i) By the company (with no possibility for changes) ii) By the worker (who can choose between several fixed work schedules, can adapt within certain limits, and entirely determines working hours)
6	Imbalanced interpersonal power relations Communication and participation with superiors refers to informal power relations of authority and discrimination, reflecting imbalanced workplace relations.	Communication and participation with superiors	Computed from responses to a combination of questions: Over the past 12 months, have you or not [yes=0; no=1]: a) been subject to formal assessment of your work performance? b) raised work-related problems with an employee representative?	For the analyses, we created a binary indicator, where 0 is the value for all positive aspects of communication and participation, and 1 is the value for all negative aspects: i) Yes ii) No
7	Lack of training Training opportunities provided by the employer (on-the-job, on-site or paid for by the employer) is considered as an indicator of internal career and skill development possibilities that reflect the capability of maintaining employment in the future. The indicator shows whether or not respondents have received such training over the last 12 months. Training paid or provided for by the worker is a potential source of inequality.	Training paid or provided by the employer	Computed from responses to a combination of questions: “Over the past 12 months, have you undergone any of the following types of training to improve your skills or not?” a) Training paid for or provided by your employer. b) On-the-job training (co-workers, supervisors).	For the analyses, we created a binary indicator, where: i) Yes, have received training. ii) No, have not received training.
8	Low control over working times (or de-standardised working time arrangements) This dimension of employment quality highlights three indicators, which are the different ways in which working time arrangements become de-standardised. These different indicators are conceptually distinct, relatively unrelated, and may affect different employee categories. Schedule unpredictability characterizes the flexibility of working times in work organization. Flexibility in commencement and/or ending the working day reflects mainly employees' needs, whereas unsocial working hours, eg, shift work, long hours, non-fixed day shifts, weekend work, having variable daily working hours, working evenings and nights), reflects mainly employers' needs (Costa, et al, 2004).b	Schedule unpredictability	Computed from responses to a combination of questions: a) How are your working time arrangements set? b) Do changes to your work schedule occur regularly? (only asked to workers who choose between several fixed work schedule); if yes c) How long before are you informed about these changes?	For the analyses, we created a binary indicator, where: i) No, sudden unpredictable changes ii) Yes, sudden changes
	Involuntary* part-time employment refers to employees who work part-time, ie, ≤35 hours per week, but wish to work more hours. It is considered an undesirable situation in relation to working times, and therefore as an indicator of low employment quality. It is often out of the worker's control, and dictated by the employer for such reasons as avoidance of labour rights and social insurance costs associated with a full-time employee. Commonly results in financial difficulties because of underemployment or implicit expectations to perform more hours than are paid.	Involuntary part-time employment.	How many hours per week would you prefer to work at present?	i) No (≥35 hrs/wk) ii) Yes (≤34 hrs/wk)
	Long/intensive working times†refers to working more than 48 hours a week. The SER ideally protects workers from excessive demands through working hour regulations; the result being working weeks of about 40 hours (Bosch 2004).c	Long/Intensive working times	How many hours do you usually work per week in your main paid job?	Non intensive (Working <48 hrs)
				Intensive (Working ≥48 hrs, and in free time)
EWCS=European Working Conditions Survey; SER=Standard Employment Relationship. *Involuntary=wants to work longer hours. †This excludes the difference between worker- or employer- induced long working hours, given the difficulty in identifying the extent of ‘free choice' in this classification (Hochschild AR. The time bind: When work becomes home and home becomes work. New York: Owl Books; 2003). aUnderhill E, Quinlan M. How precarious employment affects health and safety at work: The case of temporary agency workers. Relations Industrielles: Industrial Relations 2011;66:397-421. bCosta G, Sartori S, Akerstedt T. Influence of flexibility and variability of working hours on health and well-being. Chronobiology International 2006;23:1125-37. cBosch G. Towards a new standard employment relationship in Western Europe. British Journal of Industrial Relations 2004;42:617-36.