Model performance (Q2 & R2).

There has been an increasing shift towards individually owned leader development programs within organizations. Whilst leadership coaching is one of these and is gaining in popularity, the mechanisms of its effect remain poorly understood. We develop and investigate a model in which leadership coaching enhances leader effectiveness through coaching’s positive effect on authentic and change-oriented leadership behaviours as well as self-efficacy. To assess the model, multi-source data were collected for organizational leaders (N = 70) pre- and post-coaching. To investigate mechanisms of coaching’s effect, relations between latent change scores were assessed in structural equation modelling using partial least squares indicating that after accounting for base-line scores, coaching-related increases in authentic leadership behaviour has the largest total effect on leadership effectiveness.