Millward and Hopkins (1998) for measuring the transactional/relational distinction in contract
type, was used (see Raja et al., 2004, for discussion of scale’s psychometric properties). Our
survey instrument comprised seven items to measure the RelPC type and ten items to measure
TrPC type. The PCS was pretested for content validity with the organisation’s senior volunteer
management. The pretest resulted in only minor editorial changes to fit the volunteer context,
e.g. replacing ‘to work’ with ‘to volunteer’. Respondents were asked to respond, using a
five-point scale ranging from ‘strongly disagree’ to ‘strongly agree’, to the given statements.
Sample items associated with the TrPC included the following: “I prefer to volunteer a strictly
defined set of hours” and “I expect to benefit from any extra effort I put in”. Sample items
associated with the RelPC included the following: “I feel part of a team in this organisation”
and “I feel this organisation reciprocates the effort put in by its volunteers”. A respondent’s
score for each PC type was computed by averaging responses to the relevant set of items (each
α = 0.70).
The PsyCap variable was measured with the Psychological Capital Questionnaire (PCQ), a
24-item self-rating instrument developed by Luthans et al. (2007b). As required under the
conditions permitting its use, the instrument was administered in its exact form without any
changes to the instructions and the 6-point scale ranging from ‘strongly disagree’ to ‘strongly
agree’ (α = 0.92). The language used in the PCQ is generally context-neutral and was therefore
not considered in need of adaptation to the volunteer context. In addition, the suitability of the
PCQ for the volunteer context was reviewed and confirmed by the organisation’s senior
volunteer management. As a precaution, however, respondents were instructed explicitly in the
accompanying project information sheet to respond to all questions in the survey questionnaire
in relation to their volunteer job.