Policy function calculation from value function iterations

 

Today we consider the basic AK model and its Bellman equation:

 

  

where  or and

 

We consider the following m-state model:

 

 

 

 .

 .

 .

 

where

 

 .

 .

 .

 

and

 

 

 .

 .

 .

 

Or we consider m x m probability matrix P whose row sums are all ones.

 

Each probability lies between 0 and 1.

 

There are only m policy functions and nothing more.

 

Notice that grid method is valid only for a single value function.

 

We had better compute each policy function separately.