“…As we have seen before, {Z t } is finite dimensional if at least one of {M t } or Θ is observed, but is infinite-dimensional in the main case of interest (c) requiring joint inference. Using the Markov structure, the optimal policy response φ * t at time t is a function of the posterior state Z t , φ * t = Φ(I t , Z t , φ t− ), for some strategy rule Φ. Analytic treatment of such infinite-dimensional control problems is generally intractable; see Ludkovski and Niemi [2010], Ludkovski [2012b] for flexible numerical approximations that also rely on SMC.…”