“…An individual may have a relatively stable 'average' level of engagement, yet will likely fluctuate significantly around this level across brief periods of time. Support for this proposition is drawn from a number of diary studies based on job demands-resources (JD-R) theory (Sonnentag et al, 2010) that have established an association between a range of factors including social support (Xanthpoulou, Bakker, Heuven, Demerouti, & Schaufeli, 2008), leadership style (Tims, Bakker, & Xanthopoulou, 2011;Xanthopoulou, Bakker, Demerouti, & Schaufeli, 2009), job resources (Breevaart, Bakker, & Demerouti, 2014) and personal resources such as self-efficacy and optimism (Xanthopoulou et al, 2008;2009), and engagement at the between-person level.…”