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From |
Nick Cox <njcoxstata@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: how to do a weighted transition matrix |

Date |
Fri, 29 Apr 2011 19:58:47 +0100 |

-xttrans- does not support weights, so I don't see the point to your question about -xttrans-. Austin Nichols gave hints in his email about how to use weights in this area. Nick On Fri, Apr 29, 2011 at 7:50 PM, Hey Sky <heyskywalker@yahoo.com> wrote: > Dear Nick > > thanks for your time and kind answer. > > I think now the question connects to how Stata deals weight. > > what does it mean when I use aweight to the command tab? it seems it should not > change the result since the help file says aweight is inversely proportional to > the VARIANCE of an observation, usually represent averages, but not the value > itself. but it does have difference when with/out using the weight. > > > do you think the weight for xttrans in Stata, if it has the option, has the same > principle as tab? that is, the weight multiplies the value? if not, what would > it be to get the weighted value with command tab? > > thanks for your time and kind answer again > > Nan > from Montreal > > > > ----- Original Message ---- > From: Nick Cox <njcoxstata@gmail.com> > To: statalist@hsphsun2.harvard.edu > Sent: Fri, April 29, 2011 1:54:45 PM > Subject: Re: st: how to do a weighted transition matrix > > Thanks for the detail. From what you tell us, I gather that the > weighted matrix of transition frequencies is just the actual matrix > multiplied by the constant. The transition probabilities are > unaffected by a multiplicative constant. > > Nick > > On Fri, Apr 29, 2011 at 5:37 PM, Hey Sky <heyskywalker@yahoo.com> wrote: >> Dear Nick >> >> thanks for your reply. >> >> my research topic is about the transition probability from one state to >>another, >> e.g., white/blue collar job and self-employment within an unbalanced panel. > all >> the three states are mutural exclusive dummy variables. the weight is a >>constant >> number but not integer. it adjust the percentage of different people groups, >> e.g., there is too many refugee in the survey but less other immigrants so > that >> the stats bureau uses the weight to adjust it back to represent the real >>world. >> >> >> the following created data are almost the same with the actural one, though I >>am >> not sure about the value of the weight. I checked it once long time ago and >> vaguely remember it is just a constant number (I cannot check not due to the >> data is not at hand). I used xttrans to get the transition matrix but I have >> been required to use weights otherwise I cannot take the results to the > public. >> >> >> hope I make my question clear and thanks for any suggetsions. >> >> clear >> input id time w b s weight >> 1 1 1 0 0 1.8 >> 1 2 1 0 0 1.8 >> 1 3 0 1 0 1.8 >> 2 1 0 1 0 1.8 >> 2 2 0 1 0 1.8 >> 2 3 0 0 1 1.8 >> 3 1 0 0 1 1.8 >> 3 2 0 1 0 1.8 >> 3 3 . . . 1.8 >> 4 1 0 0 1 1.8 >> 4 2 0 1 0 1.8 >> 4 3 1 0 0 1.8 >> end >> >> >> Nan >> from Montreal >> >> >> >> >> ----- Original Message ---- >> From: Nick Cox <njcoxstata@gmail.com> >> To: statalist@hsphsun2.harvard.edu >> Sent: Fri, April 29, 2011 12:06:46 PM >> Subject: Re: st: how to do a weighted transition matrix >> >> More explanation would help. Where do the weights come from? Do they >> weight the transitions? The earlier state? The later state? Are they >> integers or not? What is your data structure? Which variables hold >> which information? Do you expect a precise answer to a vague question? >> >> At its easiest, this sounds like a transition matrix multiplied >> elementwise by a weights matrix, so save the matrices independently >> and do the multiplication in Mata. >> >> Nick >> >> On Fri, Apr 29, 2011 at 4:57 PM, > Nan from Montreal, a.k.a. Hey Sky >> <heyskywalker@yahoo.com> wrote: >> >>> I have to do a weighted transition matrix but it is not an option for the >>> command xttrans. >>> >>> I have searched the archives but did not find any discussion about >>> this question. >>> did anyone experience this before and any (other) method to deal with it? >> >> * >> * For searches and help try: >> * http://www.stata.com/help.cgi?search >> * http://www.stata.com/support/statalist/faq >> * http://www.ats.ucla.edu/stat/stata/ >> >> >> * >> * For searches and help try: >> * http://www.stata.com/help.cgi?search >> * http://www.stata.com/support/statalist/faq >> * http://www.ats.ucla.edu/stat/stata/ >> > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**st: how to do a weighted transition matrix***From:*Hey Sky <heyskywalker@yahoo.com>

**Re: st: how to do a weighted transition matrix***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: how to do a weighted transition matrix***From:*Hey Sky <heyskywalker@yahoo.com>

**Re: st: how to do a weighted transition matrix***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: how to do a weighted transition matrix***From:*Hey Sky <heyskywalker@yahoo.com>

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