中非2023世行企業(yè)調查實施報告（英文）

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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

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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.

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combinationofa4a,a2,a6a,andpanelformsstratumofeachestablishment,whichiscontainedinvariablestrata.

Thelastcompletefiscalyearforeachestablishmentiscontainedinvariablesa20m(lastmonthoflastcompletefiscalyear)anda20y(lastcompletefiscalyear).

NotethatwhenanentryintheWBESdatabaseisempty,thismeansthatthequestionwasnotaskedtothecorrespondingrespondent.Thishappenswhenthequestionisdeemedinapplicable,duetoskippatternsorotherreasons.Incaseswhenthequestionwasposed,someentryisprovided,includingdon'tknow,whichisanexampleofitemnon-response.

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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

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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

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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

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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%

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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