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teaked timing discussion in ifp_egm
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lectures/ifp_egm.md

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@@ -129,18 +129,20 @@ Markov chain taking values in $\mathsf Z$ with Markov matrix $\Pi$.
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```{note}
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The budget constraint for the household is more often written as $a_{t+1} + c_t \leq R a_t + Y_t$.
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This setup was developed for discretization.
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This setup, which is pervasive in quantitative economics, was developed for discretization.
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it means that the control is also the next period state $a_{t+1}$, which can then be restricted to a finite grid.
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It means that the control is also the next period state $a_{t+1}$, which can
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then be restricted to a finite grid.
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Computational economists are moving away from raw discretization, which allows
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the use of alternative timings, such as the one that we adopt.
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We try to avoid raw discretization when possible, since it suffers heavily from
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the curse of dimensionality.
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Our timing turns out to slightly easier in terms of minimizing state variables
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(because transient components of labor income are automatially integrated out --- see
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{doc}`this lecture <ifp_advanced>`) and studying dynamics.
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Moreover, removing discretization allows the use of alternative timings, such as the one that we adopt in this lecture.
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In practice, either timing can be used when including households in larger models.
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In fact the timing we use here is, in many cases, considerably more efficient than the traditional one.
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The reason is that transient shocks (in this lecture, the transient component of labor income) are
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automatially integrated out (instead of becoming state variables).
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```
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