Gigs of data exist from decades of surveys on employee satisfaction. This is a well researched topic with work done by many reputable firms like Hewitt, Deloitte, Kenexa, AON, Gallup and Towers Perrin. Some of the best research I've come across is from Leigh Branham in his book RE-ENGAGE who cites 6 universal engagement drivers.
Caring, competent, and engaging senior leaders
Effective managers who keep employees aligned and engaged
Effective teamwork at all levels
Job enrichment and professional growth
Valuing employee contributions
Concern for employee well being
Today, more than ever before, I see trust as a key issue impacting engagement. You can be on a great team, working with highly competent team members, serving great clients, being paid well and receiving recognition. Yet if you see people or leaders behaving without integrity and getting away with it, trust erodes and disengagement sets in.
When people are asked about career experiences where they were fully engaged, I often hear there was a high level of trust. When trust is high, work gets done faster, fewer emails are sent to clarify positions, and there are fewer meetings after the meeting. When I look at the research and talk with business leaders, a key distinction that creates an engaged workforce is trust in senior leadership.