Value function iteration

 

We consider the following maximization problem

 

          subject to

 

where both R and Q are negative as in 0506.

 

Here, we have two kinds of costs, x and v. The corresponding Bellman equation is

 

     subject to

 

We start from V0=0 and v=0.

 

When j=0

 

 

That is

 

 

When j=1

FOC w.r.t. v is

That is

Plugging this v to Bellman equation at optimum, we get

That is

We can regard it as

 

 

When j=2

FOC w.r.t. v is

That is

Plugging this v to Bellman equation at optimum, we get

That is

We can regard it as

 .

 .

 .

We go on and we find that

 

   when j=n

where

 

that is not changed at all and it starts from .

 

All we have to do is find the convergence of  in the limit and plug it into policy

 

function and value function.

 

Notice that initial value does not have to be R but we could start any point.