What are the benefits of transformational over transactional leadership? Transformational leadership is sometimes recommended as a way of motivating and inspiring followers in contrast to more transactional styles of leadership.

There is a large pop-psych literature on leadership, but I'm specifically interested in scientifically rigorous empirical evidence supporting or not supporting the value of transformational leadership.


What is the empirical support for transformational leadership?
Here is one meta analytic comparison:

http://www.ncbi.nlm.nih.gov/pubmed/15506858

Bernard M. Bass is one of the most cited researchers on this field:
Here is one of his articles but there are plenty on the net:

http://www.apa.org/pubs/journals/releases/apl-882207.pdf

I think he is also author of MLQ - multifaceted survey of leadership.

There is also revised theory by Bass and Avolio:
The implications of transactional and transformational leadership.

And also: Re-examining the components of transformational and transactional leadership using the Multi-factor Leadership; Journal of Occupational and organizational psychology. 2010.