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From | Chris Parker <cparker.phd2007@london.edu> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Re: Analyzing time series data on prices by districts & markets |
Date | Mon, 13 Jun 2011 15:47:02 +0100 |
Sorry, that last bit should be: egen statetag = tag(state) egen numstates = total(statetag) bysort date: egen stateswithprices = total(statetag) gen percentstateswithprices = stateswithprices/numstates Chris Chris Parker ________________________________ PhD Candidate | Management Science & Operations London Business School | Regent's Park | London NW1 4SA | United Kingdom Direct line +44 (0)20 7000 8816 | Email cparker.phd2007@london.edu On Mon, Jun 13, 2011 at 3:45 PM, Chris Parker <cparker.phd2007@london.edu> wrote: > > Hi Partho, > > It looks like you want to do something like this: > > > 1. For each date, the total number of markets (over all states and > > districts) for which a price is reported, and > > bysort date: gen nummarkets = _N > > > 2. The maximum number of markets for which a price is reported for any > > date in the datasets > > Are you wanting a variable with a constant equal to the maximum number > of mandis open on each day? If so: > > egen maxmarkets = max(nummarkets) > > > In addition, to do a geographical analysis, I would like to record, > > for each date > > > > 1. The number of reporting markets in each district versus the total > > no. of markets in that district, > > egen markettag = tag(market) > bysort state district: egen marketsindistrict = total(markettag) > bysort state district date: gen marketsopen = _N > gen percentmarketsopen = marketsopen/marketsindistrict > > > 2. The number of districts in each state for which prices are > > reported, versus the total no. of districts in that state > > egen districttag = tag(district) > bysort state: egen numdistricts = total(districttag) > bysort state date: egen districtswithprices = total(districttag) > gen percentdistrictswithprices = districtswithprices/numdistricts > > > 3. Similarly, the number of states for which prices are reported, > > versus the total no. of state s where a price is ever reported > > egen statetag = tag(state) > bysort state: egen numstates = total(statetag) > bysort state date: egen stateswithprices = total(statetag) > gen percentstateswithprices = stateswithprices/numstates > > > Chris > > Chris Parker > > ________________________________ > > PhD Candidate | Management Science & Operations > London Business School | Regent's Park | London NW1 4SA | United Kingdom > Direct line +44 (0)20 7000 8816 | Email cparker.phd2007@london.edu > > On Mon, Jun 13, 2011 at 3:30 PM, Partho Sarkar <partho.ss@gmail.com> wrote: > > > > Dear Dr, Cox, > > > > Many thanks for the prompt reply. I am replying to you directly > > partly because I am not sure how to post a follow-up (please excuse me > > if this is inappropriate) > > > > The data looks like this: > > > > date state mkt dist price > > 1 Asm Ca ach 1700 > > 1 Asm Ka ari 1450 > > 1 Jha Du umk 1185 > > 1 Jha Pa aka 2400 > > 2 Asm Ka ari 1750 > > 2 Ker Ch hir 2000 > > 2 Ker Ch hir 2400 > > > > And the first step of the answers for this example would be > > > > #mkts= 5 #dist=6 #states=3 > > > > > > Best regards, > > > > Partha S. Sarkar > > Consultant Econometrician > > Indicus Analytics Pvt. Ltd (www.indicus.net) > > New Delhi, India > > > > You wrote: > > > > From Nick Cox <n.j.cox@durham.ac.uk> > > To "'statalist@hsphsun2.harvard.edu'" <statalist@hsphsun2.harvard.edu> > > Subject st: RE: Analyzing time series data on prices by districts & markets > > Date Mon, 13 Jun 2011 14:27:55 +0100 > > > > The list's guidelines preclude attachments but certainly do not > > preclude ASCII text within a posting showing part of your data. > > > > Nick > > n.j.cox@durham.ac.uk > > > > In reply to my question: > > > > > > > > > > > > On Mon, Jun 13, 2011 at 6:21 PM, Partho Sarkar <partho.ss@gmail.com> wrote: > > > Hello all, > > > > > > I am quite new to Stata (and this list), and trying hard to quickly > > > pick up the skills while on the job. Would really appreciate some > > > help with this task, and please excuse if this seems too elementary! > > > > > > Problem: > > > > > > I have a large dataset which gives prices of a commodity at each date > > > for different markets across the country. The markets are classified > > > by State, District & Market (names). (The commodity is only traded in > > > some markets, in some districts, and some states). I need to get an > > > idea of the periods/dates for which the data are “sparse”, i.e., there > > > are too few of the Markets reporting a price. > > > > > > So I need, > > > > > > 1. For each date, the total number of markets (over all states and > > > districts) for which a price is reported, and > > > 2. The maximum number of markets for which a price is reported for any > > > date in the dataset > > > > > > In addition, to do a geographical analysis, I would like to record, > > > for each date > > > > > > 1. The number of reporting markets in each district versus the total > > > no. of markets in that district, > > > 2. The number of districts in each state for which prices are > > > reported, versus the total no. of districts in that state > > > 3. Similarly, the number of states for which prices are reported, > > > versus the total no. of state s where a price is ever reported > > > > > > I hope this is clear, as I think the List rules prevent me from > > > including a preview/sample of my data. > > > > > > Thank you > > > > > > P. Sarkar > > > Consultant Econometrician > > > India > > > > > > > * > > * 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/ > > > > ______________________________________________________________________ > > > > This email has been scanned by the MessageLabs Email Security System > > on behalf of the London Business School community. > > For more information please visit http://www.messagelabs.com/email > > ______________________________________________________________________ * * 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/