Tell Vensim to Use Terminal Value

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Inthanongsone
Member
Posts: 34
Joined: Thu Jan 28, 2016 6:01 pm
Vensim version: DSS

Tell Vensim to Use Terminal Value

Post by Inthanongsone »

Hello all,

I'd like to ask what commands can I use to tell Vensim to use "ONLY" the terminal value at the final time of simulations.

In Vensim model, there are Intial time (t) and Final time (T)
Assumptions:
S0 = Init Price
S1 = Strike Price for Alternative A
S2 = Strike Price for Alternative B
NPV = Sum(cash flows)dt
Production = Q(t)

In this case, I want Vensim to check for the value of NPV at Final Time if it is postive or negative in value.
For example:
Alternative 1 = IF THEN ELSE(S1 > S0 :AND: NPV( TERMINAL VALUE) < 0, S1*Q(t), S0*Q(t))
Alternative 2 = IF THEN ELSE(S2 > S1 :AND: NPV( TERMINAL VALUE) > 0, S2*Q(t), S1*Q(t))

Thank you very much for any help.

With best regards,
Inthan
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Joined: Wed Mar 05, 2003 3:10 am

Re: Tell Vensim to Use Terminal Value

Post by Administrator »

You cannot do this. The value at FINAL TIME is only calculated at FINAL TIME.

All you can really do is run the model to generate the value, then feed it back into a 2nd run.
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tomfid
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Joined: Wed May 24, 2006 4:54 am

Re: Tell Vensim to Use Terminal Value

Post by tomfid »

One option is to use the optimizer with a penalty to adjust the terminal value to the goal.

But in general, there's a really good reason for not doing this - it's acausal. No one knows the future, so using information from the future in the present is an unrealistic model of behavior.
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