p>=============================================================================</p><p>MODEL:     y = Ax + noise;    s.t.  card(x) = k</p><p>QUESTION:  what constitutes a "plausible" sparsity-inducing prior for            any given problem (here the sparse linear model above)?            For example, should p(x) really be a Laplacian !?</p><p>ANSWER:  the most plausible p(x) should resemble the ensemble average          of all possible posteriors found using a Reference Analysis          (with a suitably fla