Table 2.

Serial mediation analyses (N=242)

Effect	b	SE	BootLLCI	BootULCI
ab	0.19	0.03	0.13	0.26
a1 b1	0.04	0.02	0.01	0.09
a2 b2	0.10	0.02	0.06	0.15
a1 a3 b2	0.04	0.01	0.02	0.07
Contrasts
a1 b1 minus a2 b2	−0.06	0.03	−0.13	0.01
a1 b1 minus a1 a3 b2	0	0.02	−0.04	0.04
a2 b2 minus a1 a3 b2	0.06	0.02	0.01	0.11

Bootstrap sample size=5000. a and b represent unstandardised regression coefficients: a₁=direct effect of autonomy on optimism; a₂=direct effect of autonomy on work engagement; a₃=direct effect of optimism on work engagement; b₁=direct effect of optimism on organisational citizenship behaviour; b₂=direct effect of work engagement on organisational citizenship behaviour; ab=total indirect effect; a₁b₁=specific indirect effect through optimism; a₂ b₂=specific indirect effect through work engagement; a₁a₃b₁=specific indirect effect through optimism and work engagement

LLCI, lower limit of CI; ULCI, upper limit of CI.