Why do the arm rails on escalators often move at a different rate than the stairs?

Question

I gather it's because the arm rails are connected to a different system than the stairs are. However why would the escalator be designed in this way in the first place. Why not connect the two systems so both the stairs and the arm rail move at the same pace?

Answer 1

Handrails are connected to the same system as the steps but not in a rigid fashion.
Handrails are required by code to slip in an emergency such as someone getting fingers caught.
As the belts that drive the handrail wear the clutch system may begin to slip slightly giving a different speed.
New systems travel slightly faster than the steps, and as they wear she speed slows to slightly slower than the steps until components are replaced.

Answer 2

This is probalby to save power.