Lattice Effective Actions and Light-Quark Confinement

The positive-plaquette Manton action at weak coupling is a reasonable action for short-distance phenomena. We propose an iterative scheme for evolving this action into an effective action for longer distance scales. We report on the first step of this scheme in which we have measured ``blocked'' Creutz ratios with lattice spacing 2a at beta = 16 on a 32^4 lattice and have searched for an effective action that yields the same ratios on a 16^4 lattice. We also suggest a mechanism for quark confinement that relies upon the lightness of the u and d quarks and formulate a way of testing it in lattice simulations of QCD.