Hey all,
So Anil is right in that the bearded man wants you to test whether
sigma^2 should be modeled as functions of "r1" and "year". As for
your
parameterization of mu, the problem says to use the parameterization
you used in problem one. So you should actually feel free to include
the entirety of the covariates (which is what you did in problem one).
hope that helps --
Maya
On Sun, Feb 28, 2010 at 11:38 AM, Doshi, Anil <adoshi at hbs.edu> wrote:
> Nino,
> I believe the "explanatory variables suggested" by the bearded man are in
the intro paragraph of problem 3. Specifically, the year (year) and the South dummy (r1)
are the explanatory variables for sigma_2.
>
> Whether you use dummies r1...r6 to explain the beta parameter will probably depend on
your results from Problem Two. Did you think the bearded man was right? If you did, then
it probably makes sense to continue with the model from Problem 2. If you disagreed (i.e.
you did not reject the null hypothesis that the regional dummy variables were different
than zero), then you will probably want to stick with the model from Problem 1 to estimate
beta.
>
> I hope this helps.
> Anil
>
>
> Anil Doshi
> Doctoral Student | Technology and Operations Management
> Harvard Business School
> 302 Wyss Hall
> Boston, MA 02163
> tel 646-244-5396
> email adoshi at
hbs.edu
>
> On Feb 28, 2010, at 4:00 AM, Malekovic, Nino wrote:
>
> Hi all,
>
> In the problem 3, "Z_it is a vector of the explanatory variables suggested by
the bearded man". Are those the variables he suggested to leave out of the model, r1,
r2, r3, r4, r5 and r6? The only sensible interpretation that I have is that we do not use
these six explanatory variables for estimating ?_it. However, we use them for estimating
?_it^2 =e^(Z_it*?). Furthermore, the remaining explanatory variables (matrix X without r1,
r2, r3, r4, r5, and r6) are to be used for estimating betas, as in the problem 2.
>
> I would not like to misinterpret the instruction, and will appreciate if someone
confirmed that, or at least clarified it a bit.
>
> Best regards,
> Nino Malekovic
> MPA Candidate, Class 2011
> Harvard Kennedy School
> ________________________________________
> From: gov2001-l-bounces at
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> Sent: Saturday, February 27, 2010 12:00 PM
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> Subject: gov2001-l Digest, Vol 55, Issue 45
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> Today's Topics:
>
> ?1. pset4 posted, due thurs (Maya Sen)
> ?2. error message (Chiara Superti)
> ?3. Re: error message (Iain Osgood)
> ?4. panel data in R (Chiara Superti)
> ?5. Re: panel data in R (Maya Sen)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sat, 27 Feb 2010 09:29:06 -0500
> From: Maya Sen <msen at fas.harvard.edu>
> Subject: [gov2001] pset4 posted, due thurs
> To: "Class List for Gov 2001/E-2001" <gov2001-l at
lists.fas.harvard.edu>
> Message-ID:
> ? ? ? <16e0be401002270629o6fac0026y4cd3e47eba642041 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Hi all,
>
> Just a reminder -- pset 4 has been posted, and it's due Thursday
> before 6pm. If you are writing the replication paper, also "due"
> Thursday is an email from your group of co-authors with your intended
> paper and a few lines about why it's a good choice.
>
> Maya
>
>
> ------------------------------
>
> Message: 2
> Date: Sat, 27 Feb 2010 10:00:35 -0500
> From: Chiara Superti <csuperti at fas.harvard.edu>
> Subject: [gov2001] error message
> To: Class List for Gov 2001/E-2001 <gov2001-l at lists.fas.harvard.edu>
> Message-ID: <D42F22A7-C271-4F24-ACB5-A2F4525F5539 at fas.harvard.edu>
> Content-Type: text/plain; charset=us-ascii
>
> Hi everyone,
> I am trying to use the optim function in ps4 and I am always getting the following
error:
> Error in optim(par = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ?:
> (list) object cannot be coerced to type 'double'
>
> Could anyway tell me what I am doing wrong???
> Thanks
> Chiara
>
> ------------------------------
>
> Message: 3
> Date: Sat, 27 Feb 2010 10:13:23 -0500
> From: Iain Osgood <osgood2 at fas.harvard.edu>
> Subject: Re: [gov2001] error message
> To: "Class List for Gov 2001/E-2001" <gov2001-l at
lists.fas.harvard.edu>
> Message-ID:
> ? ? ? <e7322f8f1002270713v40c2f442j262ca82799972319 at mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hi Chiara,
> Its hard to tell without the complete code, but frequently this error
> message involves attempts to convert a dataframe (which is of mode 'list'
> and class 'dataframe') into a matrix incorrectly. ?Perhaps in your
function
> code do you have a line like as.numeric(data) when it should be
> as.matrix(data)?
> Iain
>
> On Sat, Feb 27, 2010 at 10:00 AM, Chiara Superti
> <csuperti at fas.harvard.edu>wrote:
>
>> Hi everyone,
>> I am trying to use the optim function in ps4 and I am always getting the
>> following error:
>> Error in optim(par = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ?:
>> (list) object cannot be coerced to type 'double'
>>
>> Could anyway tell me what I am doing wrong???
>> Thanks
>> Chiara
>> _______________________________________________
>> gov2001-l mailing list
>> gov2001-l at
lists.fas.harvard.edu
>>
http://lists.fas.harvard.edu/mailman/listinfo/gov2001-l
>>
>>
>