introductory guide to using stata

7/27/2019 Introductory Guide to using Stata

1/16

Norris IntroductiontoStata 20091

STM103Spring2009

INTRODUCTION TO STATA

1.DOWNLOADINGDATA:......................................................................................................................2

Assignment1preparation..........................................................................................................................3

Selectvariables...........................................................................................................................................3

2.STARTINGASTATASESSION..............................................................................................................4

Opening,Saving,andClosingthedatafile.................................................................................................5

KeepingalogrecordofaStataSession......................................................................................................5

UsingOperators..........................................................................................................................................5

3.WORKINGWITHDATA.......................................................................................................................6

Toseewhatyourselectedvariablescontain:............................................................................................6

Tolookatthe%distributionincategoricalvariables................................................................................7

Tolookatatablecombiningtwocategoricalvariables.............................................................................7

CreatingandChangingValuesofVariables................................................................................................8LabelingVariablesandValues....................................................................................................................9

UsingFunctions..........................................................................................................................................9

DeletingVariablesandObservations.........................................................................................................9

list .........................................................................................................................................................10

Analysisofcontinuous(scale)variables...................................................................................................10

Correlations..............................................................................................................................................10

EstimatingLinearModels(OLSand2StageLeastSquares).....................................................................11

EstimatingNonLinearModels(LogitandProbit)....................................................................................11

logit .........................................................................................................................................................11

probit........................................................................................................................................................12

4.MAKINGGRAPHS.............................................................................................................................12

Histogram.................................................................................................................................................12

Scatterplot................................................................................................................................................12

Bargraphs.................................................................................................................................................13

Printingyourgraph...................................................................................................................................13

5.UTILITIES.........................................................................................................................................13

ViewingtheData......................................................................................................................................13

CreatingandSubmittingaDoFile............................................................................................................13

6.CONVERTINGDATAFILES(EXCELTOSTATA)....................................................................................14

Thisprovidesabrief introductiontousingStatafortheQoGdatasetanalysis.Stata isavailableonallof

thecomputers in theKennedySchoolscomputer lab. Ifyouhaveahomecomputeryoumaywant to

purchaseacopyofStatafromtheCMO.StataisavailableforWindows98,Windows2000,WindowsME,

Windows XP, Windows NT, Macintosh, and UNIX operating systems. The Stata Users Guide is also

availablefromtheCMO.

The commands outlined below assume that you are using Stata for Windows. Throughout this text,

anythingappearing inBold font isaStatacommand,whereasanything in red italics isavariablename

whichyoushouldchangeforyourspecificanalysis.Menucommandsareindicatedas,e.g.,File|Open,to

indicatethatyoufirstgototheFilemenuandthenchoosetheOpenoption.TheBl ue Cour i er isthe

typeofoutputyoushouldgenerate. Asashortcut,youcanalsojustcopyandpasteanyofthecommand

linesheredirectlyintoyourStataCommandwindowthenrun.


2/16


1.DOWNLOADING DATA:

GototheQoGwebsite:http://www.qog.pol.gu.se/GotoData:theQoGData

2.Downloadthecorrectversionofthedataset.Tostartwork,downloadthecrosssectionaldatasetfor

Stataandsavethissomewhereclearlylabeledonyourmemorystick,harddriveorsharedserverspace.

3.AlsosavethePDFversionoftheFULLCodebooksomewheresafe;itisverylongbutaninvaluable

referencedocument.


3/16


ASSIGNMENT 1 PREPARATION

Theaimistowriteaprofessionalreportassessingandcomparingtheproblemsofdemocraticgovernance

reforminoneworldregion.Pickyourregion:

LatinAmerica

and

the

Caribbean,

Africa,

Asia,

CentralandEasternEurope,

MiddleEast

WesternEurope

Thinkaboutthekeyproblemsofdemocraticgovernanceintheregion.Fromyourexperienceandyour

reading,whataretheprioritiesforagencies?Canyourankthem?Focusonthemostimportant23issues

inthefirstinstance.Thenlookcarefullyattheshareddatasetcodebook.Startbyselecting34indicators

whichrelatetotheproblemsyouhavedecidedtofocusupon.Thesharedclassdatasetprovidesthe

followingindicators,alongwithmanyothers:

1.FreedomHouseindexofpoliticalrightsandcivilliberties

2.Polity

IV

Project

Democracy

and

Autocracy

scales

3.CheibubandGandhiDemocracyAutocracyclassification

4.VanhanenDemocracyIndex

5.WorldValuesSurvey/GlobalBarometersAttitudinalsurveys

6.Kaufmann/KrayWorldBankInstituteGoodgovernanceindicators

7.TransparencyInternationalCorruptionindex

SELECT VARIABLES

You can use the wholedataset withoutdoinganything furtherbut there are a LOTofvariables in the

dataset.Tosimplifyyourlifeandmakeitlessconfusing,forthisexerciseyouwillfinditeasiertoidentifya

subsetofkeyvariablesfromtheWhatItIslistwhichyouwanttouse.Youcanalwaysgoback to selectmorevariablesata later stage (nonearedeleted)but firstwork out

whichvariablestoputintoyoursubseti.e.whatisimportantasindicatorsofdemocraticgovernancefor

yourregion. NoteinStataitmatterswhethervariablenamesareincapitalsornot.

Selectthefirstoneslistedbelowandpickabout510toadd.Writedowndetailsinthelistbelowsothat

youhavethishandy.Look inthefullcodebookformoredetailsabouttheconstructionandmeaningof

each.

Name Briefdescription Type

cname Countryname Nominal

ht_region Globalregion:10categories Nominal

chga_regime CheibubandGhandi:Typeofdemocraticorautocraticregime Nominal

fh_status Freedom House: classification of states into free, semifree andnotfree

Ordinal

p_polity Combinedpolityscoreofdemocracyandautocracy Scale 10/+10

fh_cl FreedomHousecivilliberties Scale7pt

fh_pr FreedomHousepoliticalrights Scale7pt

wbgi_vae WorldBank:Voiceandaccountabilityestimate Scale

wbgi_pse WorldBank:Politicalstabilityestimate Scale

wbgi_gee WorldBank:Governmenteffectiveness Scale


4/16


rsf_pfi ReporterswithoutBorders:PressFreedomIndex Scale100pts

ti_cpi TransparencyInternational:CorruptionPerceptionIndex Scale100pts

2.STARTING ASTATASESSION

StartStatabylocatingthelinkonthedesktopandclicking.StataSE 8.lnk

Stataisapowerfultoolforconductingstatisticalanalyses.HereiswhatatypicalsessioninStatalookslike.

Thewindowscanbemovedaboutandresizedtosuityourpreferences.Ifyoudonotseeanyoftheseon

yourversion,gotoWindowandaddtheseuntiltheylookroughlyliketheabove.


5/16


a.HeretheResultswindowliststheoutcome.

b.TheVariableswindow,ontheleft,liststhenamesofallthevariablesincludedintheshareddataset.

c.Youcanentercommandsintwoways.Tostartlearningtheprogram,youcanusethedropdown

menus,similartothosecommoninMicrosoftprograms.Thisisusefulforbeginners.Onceyoubecomemorefamiliarwiththeprogram,youwillwanttotypeincommandsdirectly,tosavetime,usingthe

Commandwindowatthebottomcenterofthescreen. AcommandtellsStatawhattodoe.g,toopena

file,torunaregression,tocalculateameanofavariable,etc.

d.TheReviewwindowshowsalistofallthecommandsyouhavealreadyrun.(Here,itshowsthatIhave

openedadatafile.)IfyouclickonapreviouslyruncommandintheReviewwindow,itwillappearinthe

Commandwindowandyoucanedititorrunitagain.

OPENING, SAVING,AN DCLOSINGTH E DATA FILE

Youwillthenneedtoopenthedatafileyouhavesaved.Youmayneedtoboostthememoryallocated.

Setmemory

80000

File|Open

File|SaveAs

Itisalsoalwaysusefultohaveabackupcopyofyourdata.Thisway,nomatterwhatyoudotochangeor

recodethevariables,youalwayshaveacopyoftheolderversion.Itisalsousefulpracticetosaveyour

datafileattheendofeachsessionunderanewsequentialversion(egSTM103_2,STM103_3,sothatyou

havetheoldandnewestfileincaseyouneedtorevertback.

File|Exit

Wheneveryoufinish,toexitStata.

KEEPINGA LO GRECORD OF A STATA SESSION

File|log

Tosaveafile(log)ofyourresults,youwillneedtocreatealogfile.Statagivesyoutwochoicesoffile

formatsforyourlogfile,.log(textfile)and.smcl(formattedlogfile).The.smclfileswilllooknicerwhen

printed.YoushouldneverevercutandpasteyourStataoutputdirectlyintoyourreport;alwayssimplify,

cleanandtransferinaprofessionalandcleanformat.

Tostartalogfileinteractively,chooseFile|Log|Begin,selectthedirectoryyouwanttosavethelogfile

in,andgiveitaname(suchasjob1).Alternately,youcanclickonthefourthiconfromtheleftontheicon

bar,whichlookslikeascroll.

File|Log|Close

USINGOPERATORS

Statausesthefollowingarithmeticoperators:

+ add

subtract

* multiply

/ divide

^ raisetothepower


6/16


Forrelations,Statauses:

== equal

~= notequal

> greaterthan

= greaterthanorequalto


7/16


Firstletssummarizeyourselectedvariables.Type:

sum ht_region p_polity fh_cl fh_pr

Variable | Obs Mean Std. Dev. Min Max-------------+--------------------------------------------------------

ht_region | 192 4.526042 2.644633 1 10

p_polity | 160 1 14.45487 -77 10

fh_cl | 192 3.385417 1.821166 1 7

-------------+--------------------------------------------------------

fh_pr | 192 3.364583 2.156785 1 7

chga_regime | 189 .3968254 .4905386 0 1

Thisisveryusefulforlookingatyourselectedvariablestoseewhattheyarelike,whethernominal,

ordinalorscale(continuous).E.g.chga_regimeisabinary2 categoryvariable.Trythisforacoupleof

yourvariablesandaddnotestoyourselectedvarsonpage2.

summarizecanbeabbreviatedtosum.Youcanalsolookatmoredetail.eg

sumht_region,detail

Youcandothesamejustforoneselectedregion

sump_polityifht_region==1,detail

TO LOOK ATTH E%DISTRIBUTIONINCATEGORICAL VARIABLES

Forcategoricalvariables,trythefollowingwhichgeneratessomesimplefrequenciesielookatthe

numberofcountries(Freq)andthepercentcolumn.

. tab1ht_region

The Region of the Country | Freq. Percent Cum.

----------------------------------------+-----------------------------------

1. Eastern Europe and post Soviet Union | 27 14.06 14.06

2. Latin America | 20 10.42 24.48

3. North Africa & the Middle East | 20 10.42 34.90

4. Sub-Saharan Africa | 48 25.00 59.90

5. Western Europe and North America | 27 14.06 73.96

6. East Asia | 6 3.13 77.08

7. South-East Asia | 11 5.73 82.81

8. South Asia | 8 4.17 86.98

9. The Pacific | 12 6.25 93.23

10. The Caribbean | 13 6.77 100.00

----------------------------------------+-----------------------------------

Total | 192 100.00

TO LOOK ATATABLECOMBINING TW OCATEGORICALVARIABLES


8/16


tab2ht_region chga_regime, col

-> tabulation of ht_region by chga_regime

The Region of the | Type of RegimeCountry | 0. Democr 1. Dictat | Total

----------------------+----------------------+----------1. Eastern Europe and | 17 10 | 27| 14.91 13.33 | 14.29

----------------------+----------------------+----------2. Latin America | 17 3 | 20

| 14.91 4.00 | 10.58----------------------+----------------------+----------3. North Africa & the | 3 17 | 20

| 2.63 22.67 | 10.58----------------------+----------------------+----------4. Sub-Saharan Africa | 20 28 | 48

| 17.54 37.33 | 25.40----------------------+----------------------+----------5. Western Europe and | 26 0 | 26

| 22.81 0.00 | 13.76----------------------+----------------------+----------

6. East Asia | 4 2 | 6| 3.51 2.67 | 3.17

----------------------+----------------------+----------7. South-East Asia | 3 7 | 10

| 2.63 9.33 | 5.29----------------------+----------------------+----------

8. South Asia | 3 5 | 8| 2.63 6.67 | 4.23

----------------------+----------------------+----------9. The Pacific | 8 3 | 11

| 7.02 4.00 | 5.82----------------------+----------------------+----------

10. The Caribbean | 13 0 | 13| 11.40 0.00 | 6.88

----------------------+----------------------+----------Total | 114 75 | 189

| 100.00 100.00 | 100.00

CREATING AN D CHANGING VALUESOF VARIABLES

Recodeandgenerate

Thishelpstocategorizethevalueofanexistingscalevariable.Forexample,takethevariablecalled

p_politythatcontainsthe20pointPolityIVscaleforeachnationinyourstudy.Butyouwantthescale

tobecollapsedintotwotypesofregime,democracies andautocracies.Todothis,generateanew

variablecalledregimeandrecodeitasfollows:

genregime=p_polity

recoderegime 10/1=0 0/10=1

sumregime

Whenrecodingyourdata,becarefulnottooverwriteyouroriginalvariable.Youcancheckwhatyouhave

donewiththesummaryortab1

commands.Oryoumaywanttocreatesanewvariable,inthiscasefh_scale,definedasfh_clplusfh_pr:

Generatefh_scale=(fh_cl+fhpr)

Youcanuseanyformulatostandardizethescale.eg

generatefh_scale100=100(fh_cl+fh_pr)*7.1

Togenerateanewbinaryvariableforyourregion,if Africa(coded)


9/16


generateafrica =.

replace africa =1if(ht_region==4)

replace africa =0if(ht_region~=4)

Youcanabbreviatethiscommandwithgen.NotethatStatawilltellyouifanymissingvalueswere

generatedbyattemptingtoperformacalculationwithmissinginformation.Forexample,ifoneofthe

observationswasmissinginformationonhours,Statawouldsetyrhrsequaltomissingforthis

observation.(Seefurthernotesaboutmissingdatalaterinthissection.)

Onceavariablewithaparticularnamehasbeengeneratedyoucantgenerateanotherwiththesame

name.Instead,youmustreplacetheoldone.

LABELING VARIABLESAND VALUES

Labelingvariablesandvalueshelpsyoukeeptrackofhowyoucodedyourvariablesandwhattheyrepresent.Ittakesjustacoupleofsecondstoaddlabels,anditcansaveyoulotsoftimelaterwhenyou

cantrememberwhattheacodeof4meansinyourGDPcategoryvariable,forexample,orhowthe

variabledemo1differsfromdemo2.

Toattachalabeltoavariableanditsvalues:

labelvariableafricaWorldregion

labelvaluesafrica africalabel

labeldefineafricalabel 0Restoftheworld1SubSaharanAfrica

USINGFUNCTIONS Functionsarespecialcalculationsusedwithothercommands,suchasgenerateorreplace.Statahasthe

capabilitytocalculatemanyfunctions.Herearesomeexamplesofthemostcommonlyusedones.

ln(x)

Calculatesthenaturallogofx,wherexmaybeaconstantoravariablesuchasmad_gdppc.

Inacommand,youmightusethelogfunctionlikethis:

genlogGDP2006=ln(mad_gdppc)

DELETING VARIABLES AND OBSERVATIONS

drop

The drop command can delete either variables or observations. Deleting a variable removes an entire

variable (column) from the data set, whereas deleting an observation removes an entire observation

(row) from thedata set.Becarefulwhendoing this thevariablesandobservationsarepermanently


10/16


deletedonceyousavethedatafile!Itisfarbettertoretainthewholedatasetbuttofilterfortheselected

region.

Toeliminateavariable,inthiscasemad_gdppc:

dropmad_gdppcToeliminateobservations,inthiscaseEasternEuropeasaregion:

dropifht_region==1

Alternativelyyoucouldjustkeepasubsetofdata:

keepifafrica==1

LIST

Printsallvariablesandobservationstothescreen.Youllprobablyneverwanttodothissinceyourdata

setswillbetoolarge.

list

Youcanprintalimitedsetofvariables:

list fh_status

Youcouldalsoprintalimitedsetofobservationsaccordingtoanothercriteria,inthiscaseAfricabeing

equalto1:

listcnamefh_statusfh_clfh_prifht_region==3

codebook

Providesevenmoreinformation(mean,standarddeviation,range,percentiles,labels,numberofmissing

values,etc.)aboutavariable:

codebookfh_statufh_prfh_cl

ANALYSIS OF CONTINUOUS (SCALE) VARIABLES

EXAMININGMEANSBYCATEGORY

Inthiscasethecategoryisht_regionandthemeaniscalculatedforp_polity.Youcandothiswithvarious

commandseg

tableht_region,contents(meanp_polity)

tabstatp_polityfh_statusfh_clfh_pr,by(ht_region)columns(variables)

meanp_polity,

over(ht_region)

CORRELATIONS

corrfh_clfh_pr p_polity

Withsignificance(P)printedbelowinstarsforallcoefficientssignificantat.05orabove

pwcorrfh_cl fh_pr p_polity, star(5)


11/16


ESTIMATING LINEARMODELS (OLS AN D 2STAGELEASTSQUARES)

regress

Calculatesanordinaryleastsquares(OLS)regression,inthiscaseforaregressionofthedependent

p_polityontheindependentsGDPandal_ethnic.Notethatthedependentvariableisthefirst

variablelisted.

regressp_polity mad_gdppcal_ethnic

IfyouwishtoonlyincludeobservationswithAfricaequalto1intheregression:

regressp_polity mad_gdppcal_ethnicifafrica==1

Torunaregressionwithrobuststandarderrors:

regressStable2006GDP2006Africa,robust

ToruntwostageleastsquareswhereGDPisendogenousandz1"isanexogenousinstrumental

variable:

regressp_polity al_ethnic(mad_gdppc z1)

Note:Ifyourunaregressioncontainingmorethan40variables,Statawillreturnanerrorcodesaying:

matsizetoosmall

Toovercomethisproblem,resetthemaximumnumberofvariablesStatawillestimateusingthematsize

command;thenumbershouldbegreaterthanorequaltothetotalnumberofvariablesintheregression.

setmatsize150

predict

Calculatesthepredictedvalueforeachobservationusingthecoefficientsfromthelastregression

estimatedandsavestheseasavariablecalledyhat:

predictyhat

Tocalculatetheresidualforeachobservationusingthemostrecentlyestimatedregressionmodeland

savetheseasavariablecalledehat:

predictehat,residual

test

CalculatesanFtestofajointhypothesisconcerningthecoefficientsinthemostrecently

estimatedlinearregressionmodel,inthiscasewiththenullhypothesisH0: age= sex=0:

testal_ethnicmad_gdppc

ESTIMATING NO NLINEAR MODELS (LOGITAN D PROBIT)

LOGIT

Estimatesamodelsuitableforadichotomousdependentvariable.Inthiscase,thevariable

chga_regimeequals1fordemocracyand0forautocracy.

logitchga_regimeal_ethnicmad_gdppc


12/16


Ifyouwishtofindapredictedprobabilityforeachobservationbasedonthemostrecentmodelrunand

savetheseasavariablecalledphat:

predictphat

PROBIT

Estimatesamodelsuitableforadichotomousdependentvariable.Inthiscase,thevariable

chga_regimeequals1fordemocracyand0forautocracy.Ifyouwishtoestimatetheprobabilityof

chga_regimeconditionaluponal_ethnicmad_gdppc:

probitchga_regimeal_ethnicmad_gdppc

Ifyouwishtofindapredictedprobabilityforeachobservationbasedonthemostrecentmodelrunand

savetheseasavariablecalledphat:

predictphat

4.MAKING GRAPHS

Stata8hasaGraphicsmenuthatletsyoucreategraphsfromawindowsmenu,asanalternativetousing

commandlanguage.TheGraphicsmenuisaparticularlyuserfriendlywayofcreatinggraphs,sincegraphs

containsomanyoptionsforlabels,axes,etc.TheGraphicsmenuisfairlyintuitivetousesimplypull

downthemenuandchoosethetypeofgraphyouwant.Theoptionsareselfexplanatory.Forthose

interestedinusingcommandlanguagetocreategraphs,someofthebasicsarecoveredbelow,andyou

canreplyonthegraphicsmanualformorecomplicatedcreations.AlsoSPSShasbetterandfarmore

flexiblegraphics.Youmaywanttoconsiderthisprogramforthisfunctionalone.Youcanalsocutand

pastetheresultsoftablesintoExcelforflexibleformatsandcontroloverelements.

HISTOGRAM

Thisisthedefaultwhenonlyonevariableisspecified:

histogramp_polity

Youcanalsodrawanormaldensityoverthehistogram:

histogramp_polity,normal

TohaveSTATAgraphonlycertainobservations,inthiscasethoseforwhichafricais1:

histogramp_polityifafrica==1,bin(30)

Toaddatitle:

histogramp_polity,title(PolityIVRatingofLiberalDemocracyinAfrica)

SCATTERPLOT

Thisisthedefaultiftwovariablesarespecified:

scatterwbgi_geewbgi_pse

Conditions,axes,titles,labelingandreferencelinescanbespecifiedasabove.Forexample:withlabels

scatterwbgi_geewbgi_pse,t1(Effectivenessbystability)mlabel(cname)


13/16


scatterwbgi_geewbgi_pse,t1(Effectiveness bystability)

Afterperformingaregression,youmaywanttographpredictedandactualvaluesofthedependent

variableagainsttheindependentvariable:

scatter

yhat1scatterwbgi_geewbgi_pse,xlabelylabelsymbol(o.)

BAR GRAPHS

Thisisproducedwithagraphcommandfollowedbyonevariable.Asecondvariableisusedtodefine

groups.Toproduceagraphwithbarheightsrepresentingthemeanforeachgroup:

sortwbgi_gee

graphbar(mean)wbgi_gee,over(ht_region)

Conditions,yaxisoptions,mosttitles,andhorizontalreferencelinescanbespecifiedasdescribedabove

withregardtohistogram:

sortwbgi_gee

graphbar(mean)wbgi_gee,over(africa)t1(PoliticalStabilityinAfrica)t2(Title2)l1(MeanStability)

l2(AnotherTitle)yline(33000)

PRINTING YOUR GRAPH

Stataallowsyoutoprint(File|PrintGraph)andsave(File|SaveGraph)yourgraphs.Theeasiestwayto

incorporateyourgraphintoaWorddocumentistocopythegraphtotheclipboardusingEdit|Copy

Graphandthenpasteitintoyourdocument.Rememberthatallgraphsshouldhaveaclearheadline,to

illustrateyourreport,withafullnotebelowspecifyingthesourceofthedataandanynotesexplaining

variables.Allgraphsshouldbeselfcontainedwithoutlookingfurtherinyourreport.

5.UTILITIES

VIEWINGTH EDATA

Onceyouhaveopenedadataset,youmaywishtolookatthevariablesandobservationsinspreadsheet

format.Stataprovidestwowaystodothis,browseandedit.Thebrowsecommandletsyouseethe

databutnotmakechanges,whereastheeditcommandallowsyoubothtobrowseandtomakechanges.

Itisprobablybesttousebrowseunlessyouactuallyintendtomakechangestoyourdatamanually;

otherwiseyoumayaccidentallychangesomethingandruinyourdata.

Tobrowse,enterbrowseintotheCommandwindoworselecttheBrowseicon(thirdfromtheright,a

spreadsheetwithamagnifyingglassonit).Toedit,entereditintotheCommandwindoworselectthe

Editicon(fourthfromtheright,aspreadsheetwithnomagnifyingglass).

CREATING AN D SUBMITTING ADOFILE

AlthoughStatacanberuninteractivelybyjusttypingonecommandatatime,Statacommandscanalso

besubmittedinbatchesbyusingadofile.AdofileissimplyatextfilewhichcontainsaseriesofStata

commands.YouentertheStatacommandsinthesameorderasyouwouldentertheminteractively,and

Statathenrunsthesecommandsautomaticallyinsteadofyourhavingtotypetheminlinebyline.


14/16


Foryourproblemsets,itisstronglyrecommendedthatyouusedofiles.Someoftheproblemsetswill

requiremanyStatacommands,anditisinevitablethatyouwillneedtomakechangesandrunthese

seriesofcommandsanumberoftimes.Whenyouhaveallofyourcommandsinasinglefile,itismuch

easiertogobacktothatfileandmakethenecessarychangesthantohavetoretypeeverycommand.

CreatingaDo

file

Tostartcreatingadofile,clickontheDofileeditorbutton(fifthfromtheright,lookslikeanenvelope

withapencilonit),choosetheDofileeditoroptionundertheWindowmenu,ortypedoeditinthe

Commandwindow.NotethatsinceadofileisawrittenlistofcommandsasenteredintheCommand

window,youcannotusetheStatamenuswithinadofile.Insteadyouneedtousethetyped(Command

window)commands.

6.CONVERTING DATAFILES(EXCEL TO STATA)

TheeasiestwaytoconvertdatafilesistousethesoftwareprogramStatTransfer.Thisprogramisonthe

labcomputersandallowsyoutoconvertyourdatatoorfromavarietyofdifferentfileformats(Stata,SAS

Transport,Excel,SPSS,QuatroPro,FoxPro,etc.).

ToconvertafilefromExceltoStata:

a)ClickontheapplicationStatTransferintheDataAnalysisfolder.

b)SelectExcelWorksheetforInputFileType.

c)UseBrowsetoidentifytheExcelfileyouwanttoconvertfrom.(Ifthefirstrowofthe

worksheetcontainsthevariablenames,theprogramwillusetheseasthevariablenames.)

d)SelectStataVersion8astheOutputFileType.(SinceStata8.0isarecentrelease,itis

possiblethattheversionofStatTransferyoureusingwillnothaveStataVersion8asanoption.If

thisisthecase,saveitasaversion7file;youshouldstillbeabletoopenthefileinversion8.)

e)Typeinthepathandnameofthefileyouwishtocreate.f)BegintheconversionbyclickingonBeginTransfer.

StataalsoallowsyoutoreadinbinaryandASCIIfilesdirectly.However,inmostcasesitiseasier

tofirstconvertyourdatatoaspreadsheetandthenconvertittoStatausingStatTransfer.


15/16


SUMMARY OF SPSSAND STATA COMMANDS

SPSSCommand StataCommand(s)

ADDFILES append

AGGREGATE collapse

ANOVA anova

AUTORECODEdestring

encode

CASESTOVARS reshapewide

COMMENT*

/**/

COMPUTE

generate

replace

egen

CORRELATIONScorrelate

pwcorr

CROSSTABStabulate

tab2

DATALIST

infile

infix

insheet

DELETEVARIABLESkeep

drop

DESCRIPTIVES summarize

DISPLAY describeDOCUMENT notes

DOIF xyzcommandif

DOREPEAT foreach

ECHO display

ERASE erase

EXAMINEtabulatex,

summarize(y)

EXECUTE noequivalent

EXPORT noequivalent

FACTOR factor

FILELABEL labeldata

FILTER xyzcommandif(___)

FLIP xpose

FORMATS format

FREQUENCIES tabulate

SPSSCommand StataCommand(s)

GETFILE use

GETSAS fdause

GRAPH graph

IF generate__if__

IGRAPH graph

INCLUDEFILE do___

LIST list

LOGISTICREGRESSION logistic

LOOP forvalues

MATCHFILES merge

MEANStabulate__,

summarize(__)

MISSINGVALUES none

MIXED xtmixed

NOMREG mlogit

PLUM ologit

PROBIT probit

RECODE recode

RECORDTYPE noequivalent

REGRESSION regress

RELIABILITY alpha

RENAMEVARIABLES rename

SAMPLE sample

SAVE save

SELECTIFkeepif

dropif

SORTCASES sort

SPLITFILE by

SUMMARIZEtabulate___,

summarize(___)

TEMPORARY.

SELECTIF(___).xyzcommandif(___)

TTEST ttest

VALUELABELS

VARIABLELABELS


16/16


Notes:

introductory guide to using stata

Documents