abstract  Arguments based on labour market theory suggest that there may be CEO behavioural issues related to pay deviations from the labour market rate for CEO pay; however, few studies examine this phenomenon. This study attempts to address such behavioural issues by examining the influence of relative CEO underpayment on reductions in R&D spending, the differences in this relationship between firms in high R&D intensive versus low R&D intensive industries, and the moderating affect of ownership structure on the CEO underpayment and R&D spending relationship. Results suggest that relative CEO underpayment is associated with reductions in R&D spending in low R&D intensive industries and increases in R&D spending in high R&D intensive industries. Also, greater relative CEO underpayment leads to greater reductions in R&D spending in manager-controlled organizations as compared to owner-controlled organizations. This study provides evidence that pay deviations may, in fact, affect certain CEO behaviours, specifically relating to innovation.