Engagement as a result of Motivation:
Source: http://www.happinessworks.com/blog/2013/10/21/unhappiness-at-work/
Cost Benefits of Happier, Motivated Employees:
source: https://www.happinessatworksurvey.com/business-case
Effect of Empowerment as a Management Style on Worker Pyschology:
Source: http://blogs.hbr.org/2014/01/employees-perform-better-when-they-can-control-their-space/