Hello,

Hope this is the kind of research you were looking for...

Cavazotte, F., Moreno, V., & Hickmann, M. (2012). Effects of leader intelligence, personality and emotional intelligence on transformational leadership and managerial performance. The Leadership Quarterly, 23(3), 443-455.

Chicago

Harms, P. D., & Credé, M. (2010). Emotional intelligence and transformational and transactional leadership: A meta-analysis. Journal of Leadership & Organizational Studies, 17(1), 5-17.

Hunt, J. B., & Fitzgerald, M. (2013). The relationship between emotional intelligence and transformational leadership: An investigation and review of competing claims in the literature. American International Journal of Social Science, 2(8), 30-38.

Joseph, D. L., & Newman, D. A. (2010). Emotional intelligence: an integrative meta-analysis and cascading model. Journal of Applied Psychology, 95(1), 54.

http://stat-athens.aueb.gr/~jpan/Joseph-Newman-2010.pdf

Miao, C., Humphrey, R. H., & Qian, S. (2016). Leader emotional intelligence and subordinate job satisfaction: a meta-analysis of main, mediator, and moderator effects. Personality and Individual Differences, 102, 13-24.

Chicago

Mills, L. B. (2009). A meta-analysis of the relationship between emotional intelligence and effective leadership. Journal of Curriculum and Instruction, 3(2), 22.

http://www.joci.ecu.edu/index.php/JoCI/article/download/36/60

Schlaerth, A., Ensari, N., & Christian, J. (2013). A meta-analytical review of the relationship between emotional intelligence and leaders’ constructive conflict management. Group Processes & Intergroup Relations, 16(1), 126-136.

http://lib-edpsy.alzahra.ac.ir/documents/10157/39363/126.full.pdf

http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1013&context=leadershipfacpub&sei-redir=1&referer=https%3A%2F%2Fscholar.google.ca%2Fscholar%3Fq%3Dleadership%2Bemotional%2Bintelligence%2Bmeta-analysis%26btnG%3D%26hl%3Den%26as_sdt%3D0%252C5#search=%22leadership%20emotional%20intelligence%20meta-analysis%22

Thank you Adelheid Nicol.  I appreciate these links. It gives me a counter-balance of information to a keynote that I'm presenting in 3 weeks.

Not specifically re: EI but Gallup International has been doing surveys on employee engagement for decades and leadership, employee engagement, and business success have consistently been found to be related. I think the latest report was recently released. See http://www.gallup.com/poll/165269/worldwide-employees-engaged-work.aspx. Hope this helps.