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TheCentralAfricanRepublic2023WorldBankEnterpriseSurveyImplementationReport
I.Introduction
ThisdocumentprovidesinformationontheWorldBankEnterpriseSurveys(WBES)implementedintheCentralAfricanRepublicbetweenMarch2023andJune2023.TheWBEScollectbothobjectivedatabasedonfirms’day-to-dayexperiences,andperceptionsofenterprisesregardingthebusinessenvironmentinwhichtheyoperate.TheWBEScurrentlycoverover194,000firmsin155countrieswithatotalof306surveyssince2006.TheWBESarealsousedtobuildapanelofenterprisedatathatwillmakeitpossibletotrackchangesinthebusinessenvironmentovertime.1
Thisreportdescribesthesamplingdesignofthesurvey,thedatasetstructureaswellasadditionalinformationthatmaybeusefulwhenusingthedata,suchasinformationonsurveynon-responseandtheappropriateuseofthesamplingweights.
II.SamplingStructure
TheWBESusestratifiedrandomsampling,wherethepopulationofestablishmentsisfirstseparatedintonon-overlappinggroups,calledstrata,andthenrespondentsareselectedthroughsimplerandomsamplingfromeachstratum.ThedetailedmethodologyisprovidedintheSamplingNote.2Stratifiedrandomsamplinghasseveraladvantagesoversimplerandomsampling.Inparticular,it:
•producesunbiasedestimatesofthewholepopulationoruniverseofinference,aswellasatthelevelsofstratification
•ensuresrepresentativenessbyincludingobservationsinallofthosecategories
•producesmorepreciseestimatesforagivensamplesizeorbudgetallocation,and
•mayreduceimplementationcostsbysplittingthepopulationintoconvenientsubdivisions.
TheWBEStypicallyusethreelevelsofstratification:industryclassification,establishmentsize,andsubnationalregion(usedincombination).Startingin2022,theWBESbasestheindustryclassificationonISICRev.4(withearliersurveysusingISICRev.3.1).3Forregionalcoveragewithinacountry,theWBEShasnationalcoverage.
1A“panelinterview”referstoaninterviewwithabusinessthatwasalsointerviewedinthepreviousWBES.
2TheSamplingNoteisavailableat:
/content/dam/enterprisesurveys/documents/methodology/Sampling_Note-
Consolidated-2-16-22.pdf.
Forfurthermethodologicalbackgroundsee,RichardL.Scheaffer;Mendenhall,W.;
Lyman,R.,“ElementarySurveySampling”,FifthEdition,1996.
3TheWBESuniverseincludes:allmanufacturing(ISIC4.0codes10-32),services(ISIC4.0codes33,41-43,45-47,49-56,58,61,62,69-75,79,95).DetailsonsectoralcoverageandtheWBESuniverseofinferencecanbefoundintheEnterpriseSurveysManualandGuide(p.4).
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II.1StratificationCategories
TheCentralAfricanRepublic2023WBESusesthefollowingstratificationcategories:
•Industry:3categories:
•Manufacturing
•Services
•Unknown
•Size:3categories:Small(5to19employees),Medium(20to99employees),Large(100ormoreemployees),andUnknown
•Region:2categories:BanguiandBerberati
Sectoralstratificationwasdeterminedsuchthatboththemanufacturingandtheservicessectormeettheminimumcriteriaofrepresentativenessatthe7.5%marginoferrorand90%confidenceinterval.
RegionalstrataoftheCentralAfricanRepublic2023WBESwereselectedbasedontheadministrativeboundariesofcountriestwolargestcitiesandtheirsurroundingregions:BanguiandBerberati.Morespecifically,forBanguiandsurroundingareas,thesurveycoversthecityproperandthefollowingsurroundingprefectures:Lobaye,OmbelleM'poko,Kemo,OuahamandNana-GribiziPréfecture.Similarly,forBerberatiandthesurroundingarea,thecoverageincludesthecityproperandthefollowingadditionalprefectures:MambereKadei,NanaMambere,SanghaMbaéréandOuham-Pendé.Thesurveywasrestrictedtothesetwoareasprimarilyduetosecurityandlogisticalchallengesinotherpartsofthecountry.However,theareascoveredinthissurveyaccountforover98%offormalbusinessesoperatinginthecountry,basedonaconsolidatedlistofformalbusinessesobtainedfromGuichetUniquedeformalitédesEntreprises(GUFE)andtheCaisseNationaledeSécuritéSociale.ThegeographicdistributionisshowninFigure1below.
II.2Universe
Theuniverseofinferenceincludesallformal(i.e.,registered)privatesectorbusinesses(withatleast1%privateownership)andwithatleastfiveemployees.Intermsofsectoralcriteria,allmanufacturingbusinesses(ISICRev4.codes10-33)areeligible;forservicesbusinesses,thosecorrespondingtotheISICRev4codes41-43,45-47,49-53,55-56,58,61-62,69-75,79,and95areincludedintheEnterpriseSurveys.CooperativesandcollectivesareexcludedfromtheEnterpriseSurveys.Alleligibleestablishmentsmustberegisteredwiththeregistrationagency.InthecaseoftheCentralAfricanRepublic,registrationwasfromtheGuichetUniquedeformalitédesEntreprises(GUFE).Theuniversetableisthetotalnumberofeligibleestablishments,andthetableispartitionedbythestratificationgroups(industryclassification,establishmentsize,andsubnationalregion)inacountry.
FortheCentralAfricanRepublic2023WBES,theuniversetable,showninTable1below,wasgeneratedbyconsolidatingthelistofbusinessesobtainedfromGuichetUniquedeformalitédesEntreprises(GUFE)andCaisseNationaledeSécuritéSociale.Thesub-setcorrespondingto
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thestandardESuniversewasused.ThecompletenessoftheUniverseTable(andtheSamplingFrame)wascheckedandupdatedbyTNSRMSSenegal.
II.3SamplingFrame
TheWBESrequiresthemostcompleteandup-to-dateSamplingFrame,thelistofeligibleestablishmentswithinformationonindustryclassification,size,address,andothercontactinformationthatwillbeusedtorandomlyselectthesample.IncountrieswhereapreviousroundoftheWBESexists,theSamplingFramealsoincludesthePanelSamplingFrame,whichprovidesinformationaboutalltheestablishmentsthatparticipatedinthepreviousroundoftheWBESinthecountry.
TheSamplingFramefortheCentralAfricanRepublic2023WBESwasconstructedfromthefollowingsources(seecountsofestablishmentsintheframeinTable2).ThePanelSamplingFramewasconstructedusinginformationonalltheestablishmentsthatparticipatedinthetheCentralAfricanRepublic2011WBES.TheFreshSamplingFrame,i.e.,listofestablishmentsthatareintheWBESuniverseandthathavenotparticipatedintheCentralAfricanRepublic2011WBES,wasgeneratedbyconsolidatingthelistofbusinessesobtainedfromGuichetUniquedeformalitédesEntreprises(GUFE)andCaisseNationaledeSécuritéSociale.TNSRMSSenegalverifiedandupdatedthislistwithliststhroughpubliclyavailablesourcesforsomebusinessorganizationstotrytoupdatethecensusdataasmuchaspossible,whileavoidingintroducingduplicatesasmuchaspossible.
ForeveryWBES,necessarymeasuresaretakentoensurethequalityoftheframe;however,thesampleframesarenotimmunetothetypicalproblemsfoundinestablishmentsurveys:positiveratesofnon-eligibility,repetition,non-existentunits,etc.Giventheimpactthatnon-eligibleunitsincludedinthesampleuniversemayhaveontheresults,eligibilityadjustmentsmaybeneededwhencomputingtheappropriatesamplingweightsforindividualobservations(ifandonlyiftheweightsarecomputedthesamplingframethatisalsotheuniverse).Table4reportsresponseoutcomes.
II.4SampleDesign
TheWBESsampledesign,i.e.,thetargetnumberofinterviewsineachcombinationofstratificationcategories(cells),isgeneratedusingthetwoprimarycriteria:1)minimizethedifferencefromthepurelyproportionalsamplewithineachcell,and2)achieveasufficientsamplesizebystratificationcategorytoallowforestimatesofagivenlevelofprecision.4AdditionalinformationonthecriteriafordeterminingthesamplesizebystratificationcategoryisgivenintheSamplingNote,andadditionalinformationonthesampledesignisgivenintheEnterprise
4Additionalconstraintsarealsoconsideredinthedesignstage.Thesearegenerallypracticalandinclude,forexample,havingasufficientnumberofavailablecontactsinthesample.
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SurveysManualandGuide.5TheoriginalsurveydesignfortheCentralAfricanRepublic2023WBESisgiveninTable3.
III.DataCollection
ThedetailedinformationontheWBESmethodologyanddatacollectionisprovidedintheEnterpriseSurveysManualandGuide.TheinterviewsfortheCentralAfricanRepublic2023WBESwereconductedbetweenMarch2023andJune2023.Theinterviewswereconductedinthefollowinglanguages:EnglishandFrench.Formonetaryvariables,thecurrencywasCFAFranc.
III.1Questionnaire
ThestandardWBESquestionnairecoversseveraltopicsregardingthebusinessenvironmentandbusinessperformance.Thesetopicsincludegeneralfirmcharacteristics,infrastructure,salesandsupplies,managementpractices,competition,innovation,capacity,landandpermits,finance,business-governmentrelations,exposuretobribery,labor,andperformance.InformationaboutthegeneralstructureofthequestionnaireisavailableintheEnterpriseSurveysManualandGuide.
ThequestionnaireimplementedintheCentralAfricanRepublic2023WBESincludedadditionalquestionstailoredfortheBusinessReadyReportcoveringinfrastructure,trade,governmentregulations,finance,labor,andothertopics.
III.2Contractor
ThefieldworkfortheCentralAfricanRepublic2023WBESwasimplementedbyTNSRMSSenegalthroughtheirsubcontract,PongsongResearchConsulting(PORECO)S.A.R.L..TheselectionfortheimplementingagencyfollowedthestandardWorldBankprocurementpracticesthataredescribedinmoredetailintheEnterpriseSurveysManualandGuide.
III.3Samplingandscreening
SamplesaredrawnbytheEnterpriseSurveysteaminbatches,followingthestratificationandsampledesign.ThecontractorconductedathoroughscreeningprocessbeforeschedulingtheESinterviews.ResultsofthescreeningareprovidedusingtheeligibilityandstatuscodesaslistedinTable4.Incasesofunitnon-response(eitherarefusaloraninabilitytoobtainaninterviewafterexhaustiveattempts),thecontractorproceededwiththecontactthatappearednextinthelistdrawnintherespectivecell.Theprocessofsamplingandscreeningisdescribedinmoredetailinthe
EnterpriseSurveysManualandGuide.
III.4Surveyresponse
Inallsurveys,includingtheWBES,somerespondentschoosenottoparticipate.TheEnterpriseAnalysisteamandthecontractortakeallnecessarymeasurestoboostparticipation,
5TheEnterpriseSurveysManualandGuideisavailableat:
/content/dam/enterprisesurveys/documents/methodology/Enterprise-Surveys-
Manual-and-Guide.pdf
5
throughvariousmethodsofrecruitment.Thepropermanagementofthescreeningprocessandsamplereplacementensuresthattheresultingsampleremainsrandom.
Themainmeasureofsurveyparticipationistheyield,whichistheratioofthetotalnumberofachievedinterviewstothetotalnumberofcontactedestablishments.Therearetwomainelementsthatboostyields.Firstisthesurveyparticipationrate,measuredastheshareofestablishmentsthatparticipatedamongthosethatcanbeassumedtohavebeeneligible.Thesecondelementisthequalityofframe.Ifonlyasmallfractionofthecontactedestablishmentsisactuallyeligibletoparticipateinthesurvey,thenthesamplingframeisfarfromideal.ThisqualityismeasuredbytheratioofthetotalnumberofestablishmentsthatcanbeassumedtobeeligiblefortheWBESwiththetotalnumberofcontactedestablishmentsintheframe.Inotherwords:
yield=surveyresponserate*Rateofqualityoftheframe
whichcanrewrittenasfollows:
Table5providesthesemeasuresfortheCentralAfricanRepublic2023WBESandacrossitsstratificationlevels.
III.5AchievedSample
Tables6and7providecountoftheWBESinterviewscollectedforeachstratificationcell,i.e.,brokendownbyindustry,establishmentsize,andregion.Table6reportsfullsample,whileTable7showscountsofonlypanelinterviews.
III.6SamplingWeights
SincetheWBESusesstratifiedrandomsampling,individualobservationsshouldbeproperlyweightedwhenmakinginferencesaboutthepopulation,sinceunweightedestimatesarebiasedunlesssamplesizesareproportionaltothesizeofeachstratum.ForeachWBES,specialcareisgiventocorrectlycomputesamplingweights.WhenevertheUniverseisusedtodrawthesample(i.e.,SamplingFrameisthesameastheUniverse)itisimperativetoaccuratelyadjusttheuniversewithineachstratumtoaccountforthepresenceofineligibleestablishments(e.g.,thefirmdiscontinuedbusinesses,orisdeemedineligibleduetoitsbusinessactivityorhavingfewerthanfiveemployees).Propertreatmentofpanelestablishmentsisalsocrucial.DetailsabouthowtheWBESsamplingweightsarecalculatedaregivenintheSamplingNote.
Threeversionsofsamplingweightsarecalculated,dependingontheassumptionsthatdetermineeligibilityofestablishmentstobecountedtowardstheWBESuniverse.Theseassumptionsarecalledweak,medium,andstrong;andaredefinedasgiveninthetablebelow.PrevalenceofeachoftheseoutcomesfortheCentralAfricanRepublic2023WBESisgiveninTable4.AllindicatorsandanalysisconductedbytheEnterpriseSurveysteamusethesamplingweightsbasedonthemedianassumption.Tables8-10reportestimateduniversebasedontherespectiveassumption.
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Assumption
EligibilitycodesforinclusionintheWBESuniverse
Strict
1,2,3,4,16
Median
1,2,3,4,16,10,11,13
Weak
1,2,3,4,16,10,11,13,91,92,93,94,12
Fordescriptionsofeacheligibilitycode,seeTable4.
III.7Itemresponserates
Itemresponseratemustbedifferentiatedfromsurveyresponserates.Thelatterreferstoparticipationinthesurveyitself(seeSectionIII.4)whereastheformerreferstotheabsenceofresponsestospecificsurveyquestions.6TheWBES,asanysurvey,sufferfromitemnon-response;anddifferentstrategiesareusedbythedatacollectionteamtoaddressthis.Inparticular:
•Forsensitivequestions,suchasoncorruptionortaxevasion,enumeratorswereinstructedtocollecttherefusaltorespond(-8)asaseparateresponsecategoryfromdon’tknow(-9).
•Establishmentswithincompleteinformationwerere-contactedtofillgaps.
Table11providesitemresponseratesforseveralkeyvariables,brokendownacrossthestratificationlevels.
III.8DatabaseStructure
TheWBESdatafilesareorganizedinwaysthatreflectthecorrespondingquestionnaire.Thevariablesthatarestandardacrosscountrieshavethefirstletterintheirnamecorrespondtothequestionnairesectionwherethevariablebelongsinthequestionnaire,i.e.,a1denotessectionA.Allvariablesarenumericwiththeexceptionofthosevariableswithan“x”attheendoftheirnames.Thesuffix“x”denotesthatthevariableisalpha-numeric.
TheWBESdatafilescontaintwoestablishmentidentifiers,idstdandid.Theformerisaglobaluniqueidentifierofeachestablishment,whilethelatterisuniqueidentifierwithineachsurvey.ThevariableidstdcanbeusedtomatchtheWBESestablishmentone-to-oneacrossdatabases.Thevariableswweak,wmedian,andwstrongcorrespondingtosamplingweightsbasedon,respectively,weak,median,andstrongassumptionsabouteligibility(seeSectionIII.6).Thevariablestratacorrespondstothestratumofeachobservation.
Additionally,theWBESdatafilescontainmanystandardvariables.Thevariabled1a2_v4denotesthemainactivityoftheestablishment,asobtainedduringtheWBESinterview,codedinthefour-digitISICRev.4.UsersshouldnotethatthisactivitymaydifferfromtheindustryclassificationgivenintheSamplingFrame,a4a.Usersaregenerallyadvisedtouseindustrycategoriesbasedontherealizedinformationind1a2_v4.Additionalsamplinginformationiscontainedinvariablesa2(region)anda6a(size).Thevariablepanelidentifiespanelestablishments,i.e.,thosethatparticipatedintheCentralAfricanRepublic2023WBES.The
6TheWBESquestionnaireisorganizedsothatthereisalwayssomeentryinthedatabasewhenthequestionwas
posed.Anemptyentrymeansthatthequestionwasnotaskedtothecorrespondingrespondent,typically,duetoskippatterns,orlackofapplicabilityofthatquestioningeneral.
7
combinationofa4a,a2,a6a,andpanelformsstratumofeachestablishment,whichiscontainedinvariablestrata.
Thelastcompletefiscalyearforeachestablishmentiscontainedinvariablesa20m(lastmonthoflastcompletefiscalyear)anda20y(lastcompletefiscalyear).
NotethatwhenanentryintheWBESdatabaseisempty,thismeansthatthequestionwasnotaskedtothecorrespondingrespondent.Thishappenswhenthequestionisdeemedinapplicable,duetoskippatternsorotherreasons.Incaseswhenthequestionwasposed,someentryisprovided,includingdon'tknow,whichisanexampleofitemnon-response.
8
IV.UsefulLinks
TheusersoftheWBESdatamayfindthefollowinglinksuseful:
•SamplingNoteisavailableat:
/content/dam/enterprisesurveys/documents/methodolog
y/Sampling_Note-Consolidated-2-16-22.pdf
•TheEnterpriseSurveysManualandGuideisavailableat:
/content/dam/enterprisesurveys/documents/methodolog
y/Enterprise-Surveys-Manual-and-Guide.pdf
•TheWBESglobalquestionnairesareavailableat:
/en/methodology
•TheprojectsthatarecurrentlybeingimplementedbytheEnterpriseSurveysteamareavailableat:
/en/methodology/current-projects
•ThelistofallWBESdatabasesanddetailedinformationabouteachisavailablehere:
/content/dam/enterprisesurveys/documents/methodolog
y/DataDetails.xls
•ThedescriptionoftheWBESindicatorsisavailableat:
/content/dam/enterprisesurveys/documents/Indicator-
Description.pdf
9
FactSheet
SourceofUniverseTable
GuichetUniquedeformalitédesEntreprises(GUFE)
SourceofSamplingFrame
GuichetUniquedeformalitédesEntreprises(GUFE)
Stratificationsectors
Manufacturing,Services,andUnknown
Stratificationsizes
Small(5to19employees),Medium(20to99employees),Large(100+),andUnknown
Stratificationregions
BanguiandBerberati
Contractor
TNSRMSSenegalwithsub-contractorPongsongResearchConsulting(PORECO)S.A.R.L.
Fieldworkdates
March2023-June2023
Interviewlanguages
EnglishandFrench
Surveysoftware
SurveySolutions
Currencyfornominalvariables
FrancCFA
Referencefiscalyear
2023(151obs.)
SampleSize
Total:151Fresh:80Panel:71
Surveyresponserates
Yield:65.5%Responserate:84.2%Framequality:77.9%
Itemresponserates
d2:92.3%n2a:81.1%l1:100.0%allTFPvars.:50.0%
Additionaltopicscoveredinthe
questionnaire
QuestionsrelatingtotheBusinessReadyReport
Additionalsurveysavailable(ifany)
InformalSectorEnterpriseSurveycoveringtwocities(BanguiandBerberati)andMicroEnterpriseSurvey,coveringthesameregions
10
Tables
Table1:CentralAfricanRepublic2023WBESUniverse
Manufacturing
Services
Unknown
GrandTotal
Bangui
Small(5-19)
67
670
91
4,466
Bangui
Medium(20-99)
16
99
26
Bangui
Large(100-199)
9
25
4
Bangui
Unknown
282
3177
0
Berberati
Small(5-19)
4
20
5
93
Berberati
Medium(20-99)
2
1
0
Berberati
Large(100-199)
0
0
0
Berberati
Unknown
23
38
0
403
4,030
126
4,559
Source:ConsolidatedframebasedonlistofbusinessesobtainedfromGuichetUniquedeformalitédesEntreprises(GUFE)andCaisseNationaledeSécuritéSociale
Table2:CentralAfricanRepublic2023WBESSampleFrame(FreshandPanelCombined)
Manufacturing
Services
Unknown
GrandTotal
Bangui
Small(5-19)
67
670
91
4,466
Bangui
Medium(20-99)
16
99
26
Bangui
Large(100-199)
9
25
4
Bangui
Unknown
282
3177
0
Berberati
Small(5-19)
4
20
5
93
Berberati
Medium(20-99)
2
1
0
Berberati
Large(100-199)
0
0
0
Berberati
Unknown
23
38
0
403
4,030
126
4,559
SourceConsolidatedframebasedonlistofbusinessesobtainedfromGuichetUniquedeformalitédesEntreprises(GUFE)andCaisseNationaledeSécuritéSociale
11
Table3:OriginalSurveyDesign(FreshandPanelCombined)
Manufacturing
Services
Unknown
GrandTotal
Bangui
Small(5-19)
12
18
2
110
Bangui
Medium(20-99)
11
23
3
Bangui
Large(100-199)
8
10
2
Bangui
Unknown
2
19
0
Berberati
Small(5-19)
3
12
3
40
Berberati
Medium(20-99)
2
1
0
Berberati
Large(100-199)
0
0
0
Berberati
Unknown
12
7
0
50
90
10
150
Table4:ResponseOutcomes
Totals
Ratesrelativetototalcontacted
Overall
Contactsavailableinframe
4,559
Issued
252
Screeningphase
Contacted
235
Eligibles
177
75.3%
Screenerrefusals
0
0.0%
Assumedeligibles
180
76.6%
Ineligible+outoftarget
19
8.1%
Unobtainable
39
16.6%
Interviewphase(onlyifeligible)
Interviewrefusals
16
6.8%
Completeinterviews
151
64.3%
12
Table5:SurveyYieldRates
Stratification
Yield
Survey
responserate
Framequality
Panel
Fresh
60.6%
81.6%
74.2%
Panel
68.9%
86.6%
79.6%
Size
Small(5-19)
70.8%
88.5%
80.0%
Medium(20-99)
69.8%
90.2%
77.4%
Large(100+)
70.0%
77.8%
90.0%
Unknown
64.4%
82.6%
78.0%
Region
Bangui
71.3%
85.9%
83.0%
Berberati
45.3%
76.3%
59.4%
Sector
Manufacturing
60.6%
86.0%
70.4%
Services
74.3%
85.7%
86.7%
Unknown
64.4%
82.6%
78.0%
Overall
CentralAfricanRepublic2023
64.3%
83.9%
76.6%
Notes:theratesarecalculatedasdefinedinSectionIII.4
Table6:AchievedTotalSample(FreshandPanelCombined)
Manufacturing
Services
Unknown
GrandTotal
Bangui
Small(5-19)
15
25
3
122
Bangui
Medium(20-99)
9
24
3
Bangui
Large(100or
more)
4
8
2
Bangui
Unknown
2
27
0
Berberati
Small(5-19)
3
9
0
29
Berberati
Medium(20-99)
1
0
0
B
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