7For notational simplicity we express the value function and the expected
discounted value function
as functions simply of wealth and savings, but implicitly
these functions reflect the entire information set as of time t; if, for example, the income
process is not i.i.d., then information on lagged income or income shocks could be important in
determining current optimal consumption. In the remainder of the paper the dependence of
functions on the entire information set as of time
will be unobtrusively indicated, as here,
by the presence of the
subscript. For example, we will call the policy rule in period
which
indicates the optimal value of consumption
. In contrast, because we assume that the
utility function is the same from period to period, the utility function has no
subscript.