  We study linear Fisher markets with satiation. In these markets, sellers have
earning limits and buyers have utility limits. Beyond natural applications in
economics, these markets arise in the context of maximizing Nash social welfare
when allocating indivisible items to agents. In contrast to markets with either
earning or utility limits, markets with both limits have not been studied
before. They turn out to have fundamentally different properties.
  In general, the existence of competitive equilibria is not guaranteed. We
identify a natural property of markets (termed money clearing) that implies
existence. We show that the set of equilibria is not always convex, answering a
question of Cole et al. [EC'17]. We design an FPTAS to compute an approximate
equilibrium and prove that the problem of computing an exact equilibrium lies
in the intersection of complexity classes PLS and PPAD. For a constant number
of buyers or goods, we give a polynomial-time algorithm to compute an exact
equilibrium.
  We show how (approximate) equilibria can be rounded and provide the first
constant-factor approximation algorithm (with a factor of 2.404) for maximizing
Nash social welfare when agents have budget-additive valuations. Finally, we
significantly improve the approximation hardness for additive valuations to
\sqrt{8/7} > 1.069 (over 1.00008 by Lee [IPL'17]).
