塞拉利昂2023世行企業(yè)調(diào)查實(shí)施報(bào)告（英文）

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TheSierraLeone2023WorldBankEnterpriseSurveyImplementationReport

I.Introduction

ThisdocumentprovidesinformationontheWorldBankEnterpriseSurveys(WBES)implementedinSierraLeonebetweenDecember2022andApril2023.TheWBEScollectbothobjectivedatabasedonfirms’day-to-dayexperiences,andperceptionsofenterprisesregardingthebusinessenvironmentinwhichtheyoperate.TheWBEScurrentlycoverover194,000firmsin155countrieswithatotalof308surveyssince2006.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

TheSierraLeone2023WBESusesthefollowingstratificationcategories(withISIC4.0codedesignationinparenthesis):

?Industry:2categories:

?Manufacturing(SectionC)

?Services(SectionsF,G,H,I,M,andcodes58,61,62,79,95)

?Size:3categories:Small(5to19employees),Medium(20to99employees),Large(100ormoreemployees)

?Region:4categories:WesternArea,NorthernandNorthWestProvince,EasternProvince,SouthernProvince

Sectoralstratificationwasdeterminedsuchthatboththemanufacturingandtheservicessectormeettheminimumcriteriaofrepresentativenessatthe7.5%marginoferrorand90%confidenceinterval.

RegionstrataoftheSierraLeone2023WBESwereselectedbasedonadministrativedivisions.ThisincludestheWesternArea,NorthernandNorthWestProvincecombinedintoone,EasternProvince,andSouthernProvince.

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.InthecaseofSierraLeone,registrationwasfromtheCorporateAffairsCommission.Theuniversetableisthetotalnumberofeligibleestablishments,andthetableispartitionedbythestratificationgroups(industryclassification,establishmentsize,andsubnationalregion)inacountry.

FortheSierraLeone2023WBES,theuniversetable,showninTable1below,wasobtainedfromthe2016BusinessEstablishmentCensus.ThesurveywasconductedbetweenDecember2022andApril2023.TheECisthecompletecountofallestablishmentslocatedwithinthegeographicalboundariesofthecountry.Thesub-setcorrespondingtothestandardESuniversewasused.ThecompletenessoftheUniverseTable(andtheSamplingFrame)wascheckedandupdatedbyKantarTNSSenegal.

II.3SamplingFrame

TheWBESrequiresthemostcompleteandup-to-dateSamplingFrame,thelistofeligibleestablishmentswithinformationonindustryclassification,size,addressandothercontactinformationthatwillbeusedtorandomlyselectthesample.Incountrieswhereapreviousround

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oftheWBESexists,theSamplingFramealsoincludesthePanelSamplingFrame,whichprovidesinformationaboutalltheestablishmentsthatparticipatedinthepreviousroundoftheWBESinthecountry.

TheSamplingFramefortheSierraLeone2023WBESwasconstructedfromthefollowingsources(seecountsofestablishmentsintheframeinTable2):thepanelsamplingframewasusesinformationonalltheestablishmentsthatparticipatedintheSierraLeone2017WBES.TheFreshSamplingFrame,i.e.,listofestablishmentsthatareintheWBESuniverseandthathavenotparticipatedintheSierraLeone2017WBESwasobtainedfromthe2016BusinessEstablishmentCensus(sub-samplecorrespondingtotheESservicesuniverse).KantarTNSSenegal(TNSRMSSenegal)verifiedandupdatedthislistwithliststhroughpubliclyavailablesourcesforsomebusinessorganizationstotrytoupdatethecensusdataasmuchaspossible,whileavoidingintroducingduplicatesasmuchaspossible.

ForeveryWBES,necessarymeasuresaretakentoensurethequalityoftheframe;however,thesampleframesarenotimmunetothetypicalproblemsfoundinestablishmentsurveys:positiveratesofnon-eligibility,repetition,non-existentunits,etc.Giventheimpactthatnon-eligibleunitsincludedinthesampleuniversemayhaveontheresults,eligibilityadjustmentsmaybeneededwhencomputingtheappropriatesamplingweightsforindividualobservations(ifandonlyiftheweightsarecomputedthesamplingframethatisalsotheuniverse).Table4reportsresponseoutcomes.

II.4SampleDesign

TheWBESsampledesign,i.e.,targetnumberofinterviewsineachcombinationofstratificationcategories(cells),isgeneratedusingthetwoprimarycriteria:1)minimizethedifferencefromthepurelyproportionalsamplewithineachcell;and2)achieveasufficientsamplesizebystratificationcategorytoallowforestimatesofagivenlevelofprecision.4AdditionalinformationonthecriteriafordeterminingthesamplesizebystratificationcategoryisgivenintheSamplingNote,andadditionalinformationonthesampledesignisgivenintheEnterpriseSurveysManualandGuide.5TheoriginalsurveydesignfortheSierraLeone2023WBESisgiveninTable3.

III.DataCollection

ThedetailedinformationontheWBESmethodologyanddatacollectionisprovidedintheEnterpriseSurveysManualandGuide.TheinterviewsfortheSierraLeone2023WBESwereconductedbetweenDecember2022andApril2023.TheinterviewswereconductedinEnglish.

4Additionalconstraintsarealsoconsideredinthedesignstage.Thesearegenerallypracticalandinclude,forexample,havingasufficientnumberofavailablecontactsinthesample.

5TheEnterpriseSurveysManualandGuideisavailableat:

/content/dam/enterprisesurveys/documents/methodology/Enterprise-Surveys-

Manual-and-Guide.pdf

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NotethatstartingJanuary2023,thenewSierraLeoneanLeone(SLE)cameintofulleffect,whichisaredenominationoftheoldLeones(SLL)atarateof1000SLLto1SLE.AllmonetaryvariablesarereflectedinthenewSierraLeoneanLeones(SLE).Specialtrainingandadditionalprecautionsimplementedtoverifyanymonetaryvariables.

III.1Questionnaire

ThestandardWBESquestionnairecoversseveraltopicsregardingthebusinessenvironmentandbusinessperformance.Thesetopicsincludegeneralfirmcharacteristics,infrastructure,salesandsupplies,managementpractices,competition,innovation,capacity,landandpermits,finance,business-governmentrelations,exposuretobribery,labor,andperformance.InformationaboutthegeneralstructureofthequestionnaireisavailableintheEnterpriseSurveysManualandGuide.

III.2Contractor

ThefieldworkfortheSierraLeone2023WBESwasimplementedbyKantarTNSSenegal(TNSRMSSenegal)throughtheirsub-contractorLeonefields.TheselectionfortheimplementingagencyfollowedthestandardWorldBankprocurementpracticesthataredescribedinmoredetailintheEnterpriseSurveysManualandGuide.

III.3Samplingandscreening

SamplesaredrawnbytheEnterpriseSurveysteaminbatches,followingthestratificationandsampledesign.Screeningoffirmsforeligibilitywasconductedinthefield.ResultsofthescreeningareprovidedusingtheeligibilityandstatuscodesaslistedinTable4.Incasesofunitnon-response(eitherarefusaloraninabilitytoobtainaninterviewafterexhaustiveattempts),thecontractorproceededwiththecontactthatappearednextinthelistdrawnintherespectivecell.TheprocessofsamplingandscreeningisdescribedinmoredetailintheEnterpriseSurveysManualandGuide.

III.4Surveyresponse

Inallsurveys,includingtheWBES,somerespondentschoosenottoparticipate.TheEnterpriseAnalysisteamandthecontractortakeallnecessarymeasurestoboostparticipation,throughvariousmethodsofrecruitment.Thepropermanagementofthescreeningprocessandsamplereplacementensuresthattheresultingsampleremainsrandom.

Themainmeasureofsurveyparticipationistheyield,whichistheratioofthetotalnumberofachievedinterviewstothetotalnumberofcontactedestablishments.Therearetwomainelementsthatboostyields.Firstisthesurveyparticipationrate,measuredastheshareofestablishmentsthatparticipatedamongthosethatcanbeassumedtohavebeeneligible.Thesecondelementisthequalityofframe.Ifonlyasmallfractionofthecontactedestablishmentsisactuallyeligibletoparticipateinthesurvey,thenthesamplingframeisfarfromideal.ThisqualityismeasuredbytheratioofthetotalnumberofestablishmentsthatcanbeassumedtobeeligiblefortheWBESwiththetotalnumberofcontactedestablishmentsintheframe.Inotherwords:

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yield=surveyresponserate*Rateofqualityoftheframe

whichcanrewrittenasfollows:

Table5providesthesemeasuresfortheSierraLeone2023WBESandacrossitsstratificationlevels.

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.PrevalenceofeachoftheseoutcomesfortheSierraLeone2023WBESisgiveninTable4.AllindicatorsandanalysisconductedbytheEnterpriseSurveysteamusethesamplingweightsbasedonthemedianassumption.Tables8-10reportestimateduniversebasedontherespectiveassumption.

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)whereastheformerreferstotheabsenceof

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responsestospecificsurveyquestions.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.,thosethatparticipatedintheSierraLeone2017WBES.Thecombinationofa4a,a2,a6a,andpanelformsstratumofeachestablishment,whichiscontainedinvariablestrata.

Thelastcompletefiscalyearforeachestablishmentiscontainedinvariablesa20m(lastmonthoflastcompletefiscalyear)anda20y(lastcompletefiscalyear).

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

6TheWBESquestionnaireisorganizedsothatthereisalwayssomeentryinthedatabasewhenthequestionwas

posed.Anemptyentrymeansthatthequestionwasnotaskedtothecorrespondingrespondent,typically,duetoskippatterns,orlackofapplicabilityofthatquestioningeneral.

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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

2016BusinessEstablishmentCensus

SourceofSamplingFrame

2016BusinessEstablishmentCensusand2017WorldBankEnterpriseSurvey

Stratificationsectors

1.Manufacturing(SectionC)

2.Services(SectionsF,G,H,I,M,andcodes58,61,62,79,95)

Stratificationsizes

1.Small(5to19employees)

2.Medium(20to99employees)

3.Large(100+)

Stratificationregions

1.WesternArea,

2.NorthernandNorthWestProvince

3.EasternProvince

4.SouthernProvince

Contractor

KantarTNSSenegal(TNSRMSSenegal)withsub-contractorLeonefields

Fieldworkdates

December2022-April2023

Interviewlanguages

English

Surveysoftware

SurveySolutions

Currencyfornominalvariables

SierraLeoneanLeones(SLE)7

Referencefiscalyear

2022(118obs.)and2021(91obs.)

SampleSize

Total:209Fresh:112Panel:97

Surveyresponserates

Yield:65.7%Responserate:94.1%Frame

quality:69.8%

Itemresponserates

d2:100%n2a:100%l1:100%allTFPvars.:86.3%

Additionaltopicscoveredinthequestionnaire

QuestionsrelatingtotheBusinessReadyReport

Additionalsurveysavailable(ifany)

7SeesectionIIIondatacollectionfordetaileddiscussion.ThecurrencyisthenewLeones(SLE)whichwereintroducedin2022andwereinfulleffectin2023.

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Tables

Table1:SierraLeone2023WBESUniverse

Manufacturing·

Services

GrandTotal

WesternArea

Small(5-19)

302

543

955

WesternArea

Medium(20-99)

19

41

WesternArea

Large(100ormore)

14

36

NorthernandNorthWestProvince

Small(5-19)

156

262

435

NorthernandNorthWestProvince

Medium(20-99)

7

9

NorthernandNorthWestProvince

Large(100ormore)

1

0

EasternProvince

Small(5-19)

82

145

241

EasternProvince

Medium(20-99)

4

9

EasternProvince

Large(100ormore)

0

1

SouthernProvince

Small(5-19)

58

96

165

SouthernProvince

Medium(20-99)

4

7

SouthernProvinceLarge(100ormore)00

64711491796

Source:2016BusinessEstablishmentCensusand2017WorldBankEnterpriseSurvey

Table2:SierraLeone2023WBESSampleFrame(FreshandPanelCombined)

ManufacturingServicesGrandTotal

WesternArea

Small(5-19)

302

543

955

WesternArea

Medium(20-99)

19

41

WesternArea

Large(100ormore)

14

36

NorthernandNorthWestProvince

Small(5-19)

156

262

435

NorthernandNorthWestProvince

Medium(20-99)

7

9

NorthernandNorthWestProvince

Large(100ormore)

1

0

EasternProvince

Small(5-19)

82

145

241

EasternProvince

Medium(20-99)

4

9

EasternProvince

Large(100ormore)

0

1

SouthernProvince

Small(5-19)

58

96

165

SouthernProvince

Medium(20-99)

4

7

SouthernProvince

Large(100ormore)

0

0

647

1149

1796

Source:2016BusinessEstablishmentCensusand2017WorldBankEnterpriseSurvey

Table3:OriginalSurveyDesign(FreshandPanelCombined)

ManufacturingServicesGrandTotal

WesternArea

Small(5-19)

29

30

120

WesternArea

Medium(20-99)

15

13

WesternArea

Large(100ormore)

10

23

NorthernandNorthWestProvince

Small(5-19)

10

10

30

NorthernandNorthWestProvince

Medium(20-99)

4

5

NorthernandNorthWestProvince

Large(100ormore)

1

0

EasternProvince

Small(5-19)

14

6

30

EasternProvince

Medium(20-99)

3

6

EasternProvince

Large(100ormore)

0

1

SouthernProvince

Small(5-19)

16

5

30

SouthernProvince

Medium(20-99)

3

6

SouthernProvince

Large(100ormore)

0

0

105

105

210

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Table4:ResponseOutcomes

Totals

Ratesrelativetototalcontacted

OverallContactsavailableinframe

1,796

Issued

601

Contacted

318

ScreeningphaseEligible

222

69.8%

Screenerrefusals

0

0.0%

Assumedeligible

222

69.8%

Ineligible+outoftarget

70

22.0%

Unobtainable

26

8.2%

InterviewphaseInterviewrefusals

5

1.6%

(onlyifeligible)Completeinterviews

209

65.7%

Table5:SurveyYieldRates

Stratification

Yield

Surveyresponserate

Panel

Fresh

61.9%

94.1%

Panel

70.8%

94.2%

Size

Small(5-19)

77.5%

97.4%

Medium(20-99)

63.2%

92.3%

Large(100-199)

#N/A

#N/A

Region

WesternArea

55.0%

90.4%

NorthernandNorthWestProvince

83.3%

97.6%

EasternProvince

89.7%

100.0%

SouthernProvince

71.4%

96.8%

Sector

Manufacturing

69.4%

95.3%

Services

62.6%

93.0%

Overall

SierraLeone2023

65.7%

94.1%

Notes:theratesarecalculatedasdefinedinSectionIII.4.

Table6:AchievedTotalSample(FreshandPanelCombined)

ManufacturingServicesGrandTotal

WesternArea

Small(5-19)

32

37

104

WesternArea

Medium(20-99)

10

13

WesternArea

Large(100ormore)

1

11

NorthernandNorthWestProvince

Small(5-19)

18

13

40

NorthernandNorthWestProvince

Medium(20-99)

4

5

NorthernandNorthWestProvince

Large(100ormore)

0

0

EasternProvince

Small(5-19)

16

9

35

EasternProvince

Medium(20-99)

3

6

EasternProvince

Large(100ormore)

0

1

SouthernProvince

Small(5-19)

16

7

30

SouthernProvince

Medium(20-99)

2

5

SouthernProvince

Large(100ormore)

0

0

102

107

209

11

Table7:AchievedPanelSample

GrandTotal

Services

Manufacturing

WesternArea

Small(5-19)

16

13

48

WesternArea

Medium(20-99)

7

6

WesternArea

Large(100ormore)

1

5

NorthernandNorthWestProvince

Small(5-19)

7

4

11

NorthernandNorthWestProvince

Medium(20-99)

0

0

NorthernandNorthWestProvince

Large(100ormore)

0

0

EasternProvince

Small(5-19)

13

4

20

EasternProvince

Medium(20-99)

1

2

EasternProvince

Large(100ormore)

0

0

SouthernProvince

Small(5-19)

10

3

18

SouthernProvince

Medium(20-99)

2

3

SouthernProvinceLarge(100ormore)00

574097

Table8:WeakUniverseEstimates

Manufacturing

·Services·

GrandTotal

WesternArea

Small(5-19)

238

418

728

WesternArea

Medium(20-99)

14

29

WesternArea

Large(100ormore)

11

17

NorthernandNorthWestProvince

Small(5-19)

143

234

389

NorthernandNorthWestProvince

Medium(20-99)

0

7

NorthernandNorthWestProvince

MediumandLarge(20+)

5

0

EasternProvince

Small(5-19)

73

126

211

EasternProvince

Medium(20-99)

3