We consider dynamical systems : → that are extensions of a factor : → through a projection : → with shrinking fibers, i.e. such that is uniformly continuous along fibers −1 ( ) and the diameter of iterate images of fibers ( −1 ( )) uniformly go to zero as → ∞. We prove that every -invariant measureˇhas a unique -invariant lift , and prove that many properties ofˇlift to : ergodicity, weak and strong mixing, decay of correlations and statistical properties (possibly with weakening in the rates).The basic tool is a variation of the Wasserstein distance, obtained by constraining the optimal transportation paradigm to displacements along the fibers. We extend to a general setting classical arguments, enabling to translate potentials and observables back and forth between and .