  In the Entropic Dynamics (ED) derivation of the Schroedinger equation the
physical input is introduced through constraints that are implemented using
Lagrange multipliers. There is one constraint involving a "drift" potential
that correlates the motions of different particles and is ultimately
responsible for entanglement. The purpose of this work is to deepen our
understanding of the corresponding multiplier. Its main effect is to control
the strength of the drift relative to the fluctuations. We show that ED
exhibits a symmetry: models with different values of the multiplier can lead to
the same Schroedinger equation; different "microscopic" or sub-quantum models
lead to the same "macroscopic" or quantum behavior. As the multiplier tends to
infinity the drift prevails over the fluctuations and the particles tend to
move along the smooth probability flow lines. Thus ED includes the causal or
Bohmian form of quantum mechanics as a special limiting case.

Quantum Physics