Dynamic programming and Bellman Equation

 

We consider the following maximization problem

         

where

   for t=0,4,8,12,. . .

   for t=1,5,9,13,. . .

   for t=2,6,10,14,. . .

   for t=3,7,11,15,. . .

where we consider switch structure of leisure(or labor) quarterly.

 

The corresponding Bellman equations are

We guess

 

 

Then we have

FOC’s are

 and 

 and 

 and 

 and 

for each state.

 for state 1   (*)

 for state 2   (*)

 for state 3   (*)

 for state 4   (*)

On the other hand

   for state 1   (**)

   for state 2   (**)

   for state 3   (**)

   for state 4   (**)

from yesterday’s results with (*) and (**) above. For 1*’s

 for state 1

 for state 2

 for state 3 

 for state 4

 

The Bellman equations are now going to be

They are

Arranging terms and comparing the coefficients,

 

So

that is the same as yesterday and before without labor.

 

The rest is

 

where we can solve it numerically by plug them in order as in 0518.

 

We solve out and we can say that the guess is right.

 

The policy functions are

   for state 1 

   for state 2

   for state 3

   for state 4

Here, from

    for state 1

   for state 2

   for state 3

   for state 4

 

where they are constant.

 

Once we solve l*’s together with other parameters, we can get k’ for each state.