jmaih / RISE_toolbox

Solution and estimation of Markov Switching Rational Expectations / DSGE Models
BSD 3-Clause "New" or "Revised" License
105 stars 78 forks source link

Problem solving the model #186

Closed DayAfterDayAfterDay closed 4 months ago

DayAfterDayAfterDay commented 4 months ago

Dear Prof. Maih, I'm trying to solve and estimate a small DSGE and I'm having problems trying to figure how to calculate the policy function of a variable, the variable is defined as follows m{+1} = exp(-(1/theta)V{+1})/E[exp(-(1/theta)V{+1})], it should be the ratio between the exponential of the variable (without expectation) and the expected value of the same transformation. How can I do something like this? Also I the model has an occasionally bindng constraint on debt (with associated multiplier mu) but I don't want the constraint to be governed by the switching mechanism, can you tell me if the code I have written it's right? Thanks in advance for your help. ambig.txt

Andrea

jmaih commented 4 months ago

Hi Andrea,

You can break the problem into several parts using auxiliary variables.

AUX{t}= E[exp(-(1/theta)*V{+1})]

m{+1} = exp(-(1/theta)*V{+1})/AUX{t};

That said, I am not sure whether what you want to do is correct anyway. check whether the left-hand side is dated t or t+1.

Cheers,

J.

On Thu, Jun 6, 2024 at 2:43 PM Andrea Fratini @.***> wrote:

Dear Prof. Maih, I'm trying to solve and estimate a small DSGE and I'm having problems trying to figure how to calculate the policy function of a variable, the variable is defined as follows m{+1} = exp(-(1/theta)V{+1})/E[exp(-(1/theta)V{+1})], it should be the ratio between the exponential of the variable (without expectation) and the expected value of the same transformation. How can I do something like this? Thanks in advance for your help.

Andrea

— Reply to this email directly, view it on GitHub https://github.com/jmaih/RISE_toolbox/issues/186, or unsubscribe https://github.com/notifications/unsubscribe-auth/AATKBT3FQWDORLZCZQ7CMB3ZGBKQDAVCNFSM6AAAAABI4U7IOCVHI2DSMVQWIX3LMV43ASLTON2WKOZSGMZTQMJWHAYDAMY . You are receiving this because you are subscribed to this thread.Message ID: @.***>

DayAfterDayAfterDay commented 4 months ago

Dear Prof. Maih,

Thank you very much for your answer! What I need to calculate is just the ratio between the exp transformation of the random variable V and the expected value of the same quantity both in t+1 which is the definition of m{+1}, but more in general, it's possible to explicitly as RISE to calculate the conditional expectation E_t [V]? So that I can calculate m = exp(-(1/theta)V) / E_t [exp(-(1/theta)V)].

Thank you again for your help!

Andrea

jmaih commented 4 months ago

V{+1}  is interpreted as E_t(V{+1})I don’t know whether that’s what you mean. 6. juni 2024 kl. 23:22 skrev Andrea Fratini @.**>: Dear Prof. Maih, Thank you very much for your answer! What I need to calculate is just the ratio between the exp transformation of the random variable V and the expected value of the same quantity both in t+1 which is the definition of m{+1}, but more in general, it's possible to explicitly as RISE to calculate the conditional expectation E_t [V]? So that I can calculate m = exp(-(1/theta)V) / E_t [exp(-(1/theta)*V)]. Thank you again for your help! Andrea

—Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you commented.Message ID: @.***>

DayAfterDayAfterDay commented 4 months ago

Dear Prof. Maih, Thank you, that's the problem that I have, I need to calculate just the ratio between the random variable and its conditional expectation, is it possible to do in t instead of t+1?

Thanks!

Andrea

jmaih commented 4 months ago

I am not sure I understand. E_t(V{t}) = V{t}Please express the mathematical problem more clearly.J. 6. juni 2024 kl. 23:47 skrev Andrea Fratini @.***>: Dear Prof. Maih, Thank you, that's the problem that I have, I need to calculate just the ratio between the random variable and its conditional expectation, is it possible to do in t instead of t+1? Thanks! Andrea

—Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you commented.Message ID: @.***>