Intertemporal Efficiency Analysis on Indonesia Islamic Banks: A Window DEA Approach

Intertemporal Efficiency Analysis on Indonesia Islamic Banks:

A Window DEA Approach

Lina Marlina¹, Sudana^2*, Aam Slamet Rusydiiana³

1Islamic Economics Department, Siliwangi University, Tasikmalaya, Indonesia

2Islamic Economics Department, IAI PERSIS, Bandung, Indonesia

3Sharia Economics Applied Research and Training (SMART) Indonesia

*sudana@staipibdg.ac.id

Abstract

Introduction to the Problem:Measurement of the level of efficiency of Islamic banks in Indonesia is widely carried out. But almost no one has done research with the DEA window analysis approach.

Purpose/Objective Study: This paper aims to measure the efficiency of Islamic banks in Indonesia Design/Methodology/Approach: – Using Data Envelopment Analysis (DEA) method and window DEA

Findings:This research shows that the efficiency of Islamic banks that included in observations from 2011-2016 fluctuated with a mean value of 63 percent. From the perspective of efficiency stability analysis through several summary statistics such as standard deviation (SD), Long Distance per Window (LDW), Long Distance per Period (LDP) and Long Distance per Year (LDY), the relatively stable Islamic bank efficiency value is Bank Syariah MandiriSM) and BCA Syariah.

Keywords:Efficiency; Window Analysis; DEA; Islamic Bank.

Introduction

TheⁱdevelopmentⁱofⁱtheⁱIslamicⁱbankingⁱindustryⁱinⁱIndonesiaⁱshowsⁱaⁱrelativelyⁱgoodⁱtendency,

ialthoughⁱitⁱseemsⁱslow.ⁱDataⁱforⁱJulyⁱ2018,ⁱbasedⁱonⁱshariaⁱbankingⁱstatistics,ⁱtheⁱnumberⁱof

iIslamicⁱbankingⁱhasⁱreachedⁱ13ⁱIslamicⁱCommercialⁱBanks,ⁱ21ⁱIslamicⁱBusinessⁱUnitsⁱandⁱ168

iIslamicⁱRuralⁱBanksⁱwithⁱaⁱtotalⁱnetworkⁱofⁱ2,460ⁱofficesⁱthroughoutⁱIndonesiaⁱ(OtoritasⁱJasa

iKeuangan,ⁱ2018).

Meanwhile,ⁱaccordingⁱtoⁱtheⁱGlobalⁱIslamicⁱFinanceⁱReportⁱ2017,ⁱtheⁱIslamicⁱfinance

iindustryⁱinⁱIndonesiaⁱisⁱrankedⁱseventhⁱinⁱtheⁱworldⁱafterⁱMalaysia,ⁱIran,ⁱSaudiⁱArabia,ⁱUAE,

iKuwaitⁱandⁱPakistan.ⁱTheⁱindexⁱvalueⁱofⁱtheⁱIndonesianⁱIslamicⁱfinanceⁱindustryⁱinⁱ2017ⁱis

i24.21ⁱonⁱaⁱscaleⁱofⁱ100ⁱandⁱranksⁱ7thⁱinⁱtheⁱworldⁱ(GIFR,ⁱ2017).ⁱInⁱfact, ⁱIndonesiaⁱisⁱstill

irelativelyⁱunableⁱtoⁱexploitⁱtheⁱexistingⁱpotentialⁱrelatedⁱtoⁱtheⁱIslamicⁱfinanceⁱeconomy.ⁱ

Apartⁱfromⁱtheseⁱdata,ⁱtheⁱ2016ⁱtargetⁱlaunchedⁱbyⁱBankⁱIndonesiaⁱinⁱachievingⁱaⁱ5%

imarketⁱshareⁱhasⁱnotⁱbeenⁱsatisfactory.ⁱTheⁱgrowthⁱthatⁱoccursⁱinⁱIslamicⁱbanksⁱisⁱnotⁱmuch

ibetterⁱwhenⁱcomparedⁱtoⁱtheⁱincreaseⁱinⁱtheⁱmarketⁱshareⁱofⁱIslamicⁱbanksⁱthemselves.ⁱThe

iunattainableⁱtargetⁱmarketⁱforⁱshariaⁱbanksⁱinⁱ2016ⁱisⁱaⁱphenomenonⁱtoⁱevaluateⁱtheⁱoverallⁱlevel

iofⁱefficiencyⁱofⁱIslamicⁱbankingⁱinⁱIndonesia.ⁱVariousⁱkindsⁱofⁱobstaclesⁱsuchⁱasⁱcompetition

ifactors,ⁱconversionⁱofⁱIslamicⁱbusinessⁱunitsⁱintoⁱIslamicⁱcommercialⁱbanks, ⁱsoⁱthatⁱaⁱlotⁱof

iinvestmentⁱvalueⁱmustⁱbeⁱspent,ⁱconsequentlyⁱinefficiencyⁱbecomesⁱanⁱobstacleⁱinⁱheadⁱtoⁱhead

iwithⁱconventionalⁱbanking.ⁱ

Inⁱassessingⁱefficiencyⁱlevel,ⁱDataⁱEnvelopmentⁱAnalysisⁱ(DEA)ⁱisⁱrelativelyⁱmoreⁱused.

iDEAⁱisⁱwidelyⁱusedⁱtoⁱmeasureⁱtheⁱlevelⁱofⁱtechnicalⁱefficiencyⁱandⁱeconomiesⁱofⁱscaleⁱofⁱthe

ibankingⁱindustryⁱandⁱotherⁱfinancialⁱinstitutions.ⁱThisⁱisⁱconsistentⁱwithⁱtheⁱresearchⁱconducted

ibyⁱRaniⁱetⁱal.ⁱ(2017),ⁱKamarudin,ⁱet.ⁱalⁱ(2016);ⁱOzdemirⁱ(2013);ⁱShahrekiⁱ(2012);ⁱandⁱTsolas

iandⁱDimitrisⁱ(2012).ⁱLikewise,ⁱRusydianaⁱ(2018a,ⁱ2018b),ⁱRusydianaⁱ&ⁱSanregoⁱ(2018),ⁱand

iRusydianaⁱ&ⁱFirmansyahⁱ(2017).

ButⁱtheⁱresultsⁱinⁱmeasuringⁱtheⁱefficiencyⁱofⁱDEAⁱhaveⁱrelativeⁱproperties.ⁱThatⁱis,ⁱwhen

itheⁱdataⁱsetⁱincreases,ⁱtheⁱmeasurementⁱresultsⁱhaveⁱaⁱdifferentⁱtendency.ⁱSo,ⁱtoⁱovercomeⁱthis

iproblem,ⁱCharnesⁱetⁱal.ⁱ(1985)ⁱthenⁱintroducedⁱtheⁱDEAⁱwindowⁱanalysisⁱconcept.ⁱDEAⁱwindow

ianalysisⁱorⁱoftenⁱcalledⁱDEWAⁱisⁱanⁱextensionⁱofⁱDEAⁱorⁱDEAⁱversionⁱwithⁱtimeⁱdependency.ⁱIn

irelationⁱtoⁱlookingⁱatⁱvariationsⁱinⁱtheⁱvalueⁱofⁱintertemporalⁱefficiency,ⁱCharnesⁱetⁱal.ⁱ(1985)

ithenⁱproposedⁱaⁱtechniqueⁱcalledⁱwindowⁱanalysisⁱinⁱDEA.ⁱWindowⁱanalysisⁱisⁱableⁱtoⁱmeasure

itheⁱperformanceⁱofⁱaⁱDMUⁱfromⁱtimeⁱtoⁱtimeⁱbyⁱtreatingⁱitⁱasⁱaⁱdifferentⁱentityⁱinⁱeachⁱperiod.

Thisⁱstudyⁱhasⁱseveralⁱobjectives. ⁱFirst,ⁱitⁱmeasuresⁱtheⁱlevelⁱofⁱefficiencyⁱofⁱIslamic

ibanksⁱinⁱIndonesiaⁱwhichⁱareⁱobserved,ⁱinⁱthisⁱcaseⁱtheⁱShariaⁱCommercialⁱBankⁱfromⁱtheⁱperiod

i2011-2016. ⁱSecond, ⁱconduct ⁱintertemporal ⁱefficiency ⁱanalysis ⁱthrough ⁱthe ⁱDEA ⁱwindow

ianalysisⁱapproach,ⁱbyⁱlookingⁱatⁱresultsⁱperⁱyearⁱ(LDY),ⁱperⁱwindowⁱ(LDW),ⁱandⁱoverallⁱ(LDP).

iThisⁱisⁱdoneⁱtoⁱverifyⁱtheⁱresultsⁱof DEAⁱefficiencyⁱwhichⁱareⁱrelativeⁱinⁱnatureⁱandⁱtendⁱto

ichangeⁱwhenⁱtheⁱdataⁱsetⁱisⁱdifferent.

Methodology

ToⁱmonitorⁱchangesⁱinⁱtheⁱlevelⁱofⁱefficiencyⁱofⁱIslamicⁱbanksⁱfromⁱtimeⁱtoⁱtimeⁱcarriedⁱout

iWindowⁱDEAⁱ(Charnesⁱet.al,ⁱ1985).ⁱThisⁱstudyⁱusedⁱaⁱthree-yearⁱwindowⁱanalysisⁱsoⁱthatⁱfor

ieach ⁱanalysisⁱ72ⁱ(3ⁱtimesⁱ24)ⁱDMUsⁱwereⁱobtainedⁱinⁱwhichⁱtheⁱsameⁱDMUsⁱforⁱdifferent

iperiodsⁱofⁱtimeⁱwereⁱconsideredⁱasⁱdifferentⁱDMUs.ⁱTherefore,ⁱbenchmarkingⁱisⁱnotⁱonlyⁱdone

ionⁱtheⁱDMUⁱpeerⁱbutⁱalsoⁱonⁱitsⁱownⁱperformance.ⁱTheⁱtotalⁱnumberⁱofⁱshariaⁱcommercialⁱbanks

ithatⁱareⁱtheⁱobjectⁱofⁱresearchⁱareⁱ8ⁱIslamicⁱbanks.ⁱTheⁱselectionⁱofⁱtheⁱ8ⁱIslamicⁱbanksⁱstudiedⁱis

ibecauseⁱonlyⁱtheseⁱBUSsⁱhaveⁱstartedⁱandⁱhaveⁱfinancialⁱreportsⁱsinceⁱ2011.

Dataⁱonⁱinputⁱandⁱoutputⁱvariablesⁱareⁱobtainedⁱfromⁱtheⁱbalanceⁱsheetⁱandⁱprofitⁱandⁱloss

iof ⁱeach ⁱbank. ⁱTwo ⁱinputs ⁱand ⁱtwo ⁱoutputs ⁱare ⁱused ⁱto ⁱmeasure ⁱthe ⁱefficiency ⁱof ⁱsharia

icommercialⁱbanksⁱenteringⁱobservation.ⁱAsⁱinputⁱvariablesⁱareⁱDepositorⁱFunds/DPKⁱ(X1)ⁱand

iPersonnelⁱCostsⁱ(X2).ⁱMeanwhileⁱforⁱtheⁱoutputⁱvariable,ⁱnamelyⁱtheⁱamountⁱofⁱfinancingⁱgiven

i(Y1)ⁱandⁱOperatingⁱIncomeⁱ(Y2).ⁱTheⁱuseⁱofⁱdepositsⁱandⁱfinancingⁱinⁱinput-outputⁱbecauseⁱthis

istudyⁱusesⁱanⁱintermediationⁱapproach.ⁱ

TheⁱanalysisⁱtoolsⁱusedⁱinⁱthisⁱstudyⁱareⁱMaxDEAⁱ7.1ⁱtoⁱmeasureⁱtheⁱlevelⁱofⁱefficiency

iofⁱallⁱIslamicⁱbankⁱDMUsⁱduringⁱtheⁱ2011-2016ⁱperiod.ⁱAnalysisⁱforⁱefficiencyⁱmeasurement

iwillⁱbeⁱcarriedⁱoutⁱ2ⁱtimes.ⁱTheⁱfirstⁱisⁱtheⁱcalculationⁱofⁱstandardⁱefficiencyⁱwithⁱtheⁱCRSⁱor

iCCRⁱapproachⁱintroducedⁱbyⁱCharnesⁱetⁱal.ⁱ(1978).ⁱTheⁱsecondⁱefficiencyⁱcalculationsⁱwith

iwindowⁱanalysis.ⁱInⁱgeneralⁱtheⁱmathematicalⁱformulaⁱusedⁱforⁱtheⁱDEAⁱwindowⁱisⁱasⁱfollows,

iwhereⁱMⁱisⁱtheⁱaverageⁱlevelⁱofⁱefficiencyⁱandⁱKⁱisⁱtheⁱlengthⁱofⁱtheⁱwindowⁱ(windowⁱlength).

𝑀𝑙= ^𝑡=1

𝑀−𝐾+1

∑

𝑗=1 𝑖+𝐾−1

∑ .𝐸_𝑖,𝑗

𝐾 𝑥 (𝑀−𝐾+1), 𝑙 = 1, 𝐿, 𝑁

As ⁱrecommended ⁱby ⁱCooper ⁱetⁱal. ⁱ(2011),ⁱaⁱtableⁱofⁱresultsⁱofⁱtheⁱanalysisⁱwindow

icalculationⁱcanⁱbeⁱusedⁱtoⁱsimultaneouslyⁱcheckⁱrelativeⁱefficiencyⁱstabilityⁱthroughⁱseveral

isummaryⁱstatisticsⁱsuchⁱasⁱstandardⁱdeviationⁱ(SD),ⁱLongⁱDistanceⁱperⁱWindowⁱ(LDW),ⁱLong

iDistanceⁱperⁱPeriodⁱ(LDP)ⁱorⁱLongⁱDistanceⁱperⁱYearⁱ(LDY).ⁱTheseⁱfourⁱmeasurementsⁱcanⁱbe

iusedⁱasⁱanⁱanalysisⁱofⁱtheⁱefficiencyⁱstabilityⁱachievedⁱbyⁱeachⁱDMU.

Standard ⁱdeviation ⁱis ⁱa ⁱstandard ⁱdeviation ⁱthat ⁱmeasures ⁱthe ⁱlarge ⁱdifferenceⁱinⁱthe

iaverageⁱlevelⁱofⁱefficiencyⁱofⁱtheⁱDMUⁱperⁱwindow.ⁱTheⁱsmallerⁱtheⁱstandardⁱdeviationⁱvalue,

ishowsⁱtheⁱmoreⁱstableⁱtheⁱefficiencyⁱvalueⁱachievedⁱbyⁱeachⁱDMU,ⁱinⁱthisⁱcaseⁱIslamicⁱbanks.

iLongⁱDistanceⁱperⁱWindowⁱ(LDW)ⁱshowsⁱtheⁱbiggestⁱdifferenceⁱfromⁱefficiencyⁱfiguresⁱinⁱone

iwindow.ⁱTheⁱsmallerⁱLDWⁱvalueⁱmeansⁱthatⁱtheⁱefficiencyⁱvalueⁱachievedⁱbyⁱeachⁱIslamicⁱbank

iisⁱmoreⁱstable,ⁱandⁱotherwise.

Long ⁱDistance ⁱperⁱallⁱPeriodsⁱ(LDP)ⁱexplainsⁱtheⁱbiggestⁱdifferenceⁱfromⁱefficiency

ifigures ⁱin ⁱall ⁱobservationⁱperiods. ⁱTheⁱsmallerⁱtheⁱLDPⁱvalueⁱindicatesⁱtheⁱmoreⁱstableⁱthe

iefficiencyⁱvalueⁱachievedⁱbyⁱeachⁱIslamicⁱbank,ⁱandⁱviceⁱversa.ⁱTheⁱlastⁱisⁱLongⁱDistanceⁱper

iYearⁱ(LDY).ⁱLDYⁱshowsⁱtheⁱbiggestⁱdifferenceⁱfromⁱefficiencyⁱfiguresⁱinⁱoneⁱyear.ⁱSimilarⁱto

iLDW ⁱand ⁱLDP, ⁱthe ⁱsmaller ⁱthe ⁱLDY ⁱvalue ⁱindicates ⁱthe ⁱmore ⁱstable ⁱthe ⁱefficiency ⁱvalue

iachievedⁱbyⁱeachⁱDMU,ⁱandⁱotherwise.

Results and Discussion

Theⁱoutput-orientedⁱDEAⁱapproachⁱisⁱappliedⁱtoⁱpanelⁱdata,ⁱfromⁱ8ⁱShariaⁱCommercial

iBanks ⁱin ⁱIndonesia ⁱin ⁱ2011-2016. ⁱThus ⁱthe ⁱtotal ⁱnumber ⁱof ⁱobservations ⁱto ⁱcalculate ⁱthe

iefficiency ⁱvalue ⁱof ⁱallⁱbankingⁱunitsⁱisⁱ48.ⁱAtⁱtheⁱbeginningⁱitⁱhasⁱbeenⁱdescribed,ⁱthatⁱthe

inon-parametricⁱmethodⁱisⁱdividedⁱinⁱtwoⁱbasedⁱonⁱtheⁱReturnⁱtoⁱScaleⁱ(RTS)ⁱassumption,ⁱnamely

iConstantⁱReturnⁱtoⁱScaleⁱ(CRS)ⁱandⁱVariableⁱReturnⁱtoⁱScaleⁱ(ⁱVRS).ⁱByⁱestimatingⁱtheⁱfrontier

iusing ⁱthe ⁱCRS ⁱand ⁱVRS ⁱapproach, ⁱitⁱcanⁱdecomposeⁱtheⁱTechnicalⁱEfficiencyⁱonⁱtheⁱCRS

iapproach ⁱ(TE_CRS) ⁱinto ⁱthe ⁱPure ⁱTechnicalⁱEfficiencyⁱ(TE_VRS)ⁱandⁱScaleⁱEfficiency.ⁱFrontier

iefficiency ⁱanalysis ⁱis ⁱan ⁱanalysis ⁱof ⁱbest ⁱpractice ⁱfrom ⁱthe ⁱentire ⁱdataset ⁱused ⁱusing ⁱthe

iinput-outputⁱapproach.

i

Theⁱresultsⁱinⁱtheⁱtableⁱbelowⁱillustrateⁱaⁱsummaryⁱofⁱtheⁱaverageⁱefficiencyⁱscoresⁱofⁱall

iSharia ⁱCommercial ⁱBanks ⁱ(BUS) ⁱin ⁱIndonesia ⁱwhich ⁱwere ⁱincluded ⁱin ⁱobservations ⁱfrom

i2011-2016. ⁱFluctuating ⁱTechnical ⁱEfficiency ⁱthroughout ⁱthe ⁱstudy ⁱperiod, ⁱwith ⁱthe ⁱlowest

iaverageⁱvalueⁱinⁱ2012ⁱatⁱ58ⁱpercent.ⁱ

The ⁱtable ⁱalso ⁱshows ⁱthat ⁱIslamic ⁱCommercial ⁱBanksⁱinⁱIndonesiaⁱhaveⁱshownⁱthat

ioverallⁱtechnicalⁱefficiencyⁱ(overall)ⁱthroughoutⁱtheⁱstudyⁱperiodⁱisⁱ63ⁱpercent.ⁱItⁱcanⁱbeⁱread,

ithatⁱthroughⁱtheⁱimplementationⁱofⁱbetterⁱmanagementⁱpracticesⁱShariaⁱCommercialⁱBanksⁱin

iIndonesiaⁱcanⁱproduceⁱoutputⁱwithⁱtheⁱsameⁱvolumeⁱ(identicalⁱvolume),ⁱusingⁱonlyⁱ63ⁱpercentⁱof

ithe ⁱtotal ⁱinput. ⁱIn ⁱthis ⁱcase ⁱSharia ⁱCommercial ⁱBanks ⁱhave ⁱless ⁱgood ⁱaverage ⁱefficiency,

ialthoughⁱtheyⁱcannotⁱalsoⁱbeⁱcalledⁱbad.

Tabel.ⁱ2.ⁱCRSⁱEfficiencyⁱofⁱBUSⁱinⁱIndonesiaⁱ2011-2016

CRS EFFICIENCY 2011 2012 2013 2014 2015 2016 Mean

BSM 0,65 0,63 0,64 0,73 0,68 0,61 0,66

BMI 0,75 0,79 0,71 0,71 0,60 0,69 0,71

BRIS 0,74 0,68 0,63 0,65 0,68 0,63 0,67

BNIS 0,61 0,58 0,54 0,53 0,66 0,73 0,61

Mega 0,46 0,36 0,40 0,49 0,53 0,47 0,45

Panin 0,61 0,44 0,66 1,00 0,82 0,88 0,74

BSB 0,83 0,71 0,66 0,73 0,78 0,76 0,75

BCAS 0,47 0,48 0,49 0,53 0,61 0,68 0,54

Mean 0,64 0,58 0,59 0,67 0,67 0,68 0,63

Furthermore,ⁱasⁱrecommendedⁱbyⁱCooperⁱetⁱal.ⁱ(2011),ⁱaⁱtableⁱofⁱresultsⁱofⁱtheⁱanalysis

iwindow ⁱcalculation ⁱcan ⁱbe ⁱused ⁱfor ⁱrelative ⁱefficiency ⁱstability ⁱanalysis ⁱthrough ⁱseveral

isummaryⁱstatisticsⁱsuchⁱasⁱstandardⁱdeviationⁱ(SD),ⁱLongⁱDistanceⁱperⁱWindowⁱ(LDW),ⁱLong

iDistanceⁱperⁱPeriodⁱ(LDP)ⁱandⁱLongⁱDistanceⁱperⁱYearⁱ(LDY).ⁱTheseⁱfourⁱmeasurementsⁱcanⁱbe

iusedⁱasⁱanⁱanalysisⁱofⁱtheⁱefficiencyⁱstabilityⁱachievedⁱbyⁱeachⁱDMU.ⁱTheⁱsmallerⁱtheⁱfourth

ivalueⁱofⁱtheⁱmeasurementⁱabove,ⁱshowsⁱtheⁱmoreⁱstableⁱtheⁱefficiencyⁱvalueⁱachievedⁱbyⁱeach

iDMU,ⁱinⁱthisⁱcaseⁱIslamicⁱbanks. ⁱTheⁱfollowingⁱbelowⁱareⁱtheⁱresultsⁱofⁱtheⁱDEAⁱwindow

ianalysisⁱforⁱIslamicⁱbanksⁱinⁱIndonesiaⁱinⁱtheⁱperiodⁱ2011ⁱtoⁱ2016.ⁱTheⁱanalysisⁱisⁱdividedⁱintoⁱin

i4ⁱwindowsⁱwithⁱeachⁱyearⁱlengthⁱperⁱwindowⁱisⁱ3ⁱyears.

Tabelⁱ3.ⁱDEAⁱWindowⁱAnalysisⁱofⁱBUSⁱinⁱIndonesiaⁱ2011-2016

TheⁱresultsⁱofⁱtheⁱcalculationⁱofⁱtheⁱDEAⁱwindowⁱanalysisⁱforⁱ8ⁱshariaⁱcommercialⁱbanks

i(BUS) ⁱinⁱIndonesiaⁱduringⁱtheⁱperiodⁱinⁱ2011-2016ⁱcanⁱbeⁱseenⁱinⁱtheⁱfollowingⁱtable.ⁱFor

iexample,ⁱBNISⁱhasⁱrelativelyⁱnoⁱsignificantⁱchangesⁱfromⁱ2011-2013ⁱinⁱtheⁱfirstⁱwindowⁱ(with

iefficiencyⁱvaluesⁱofⁱ76%,ⁱ72%ⁱandⁱ71%),ⁱaccordingⁱtoⁱ2012-2014ⁱinⁱtheⁱsecondⁱwindowⁱ(with

iefficiencyⁱvaluesⁱofⁱ61%,ⁱ64%ⁱandⁱ67ⁱ%)ⁱalsoⁱbetweenⁱ2013-2015ⁱinⁱtheⁱthirdⁱwindowⁱ(with

iefficiencyⁱvaluesⁱofⁱ65%,ⁱ68%ⁱandⁱ71%).ⁱTheⁱBNISⁱexperiencedⁱaⁱslightⁱincreaseⁱinⁱefficiency

ivaluesⁱinⁱtheⁱfourthⁱwindowⁱofⁱ2014-2016ⁱwithⁱefficiencyⁱvaluesⁱofⁱ79%,ⁱ86%ⁱandⁱ82%.ⁱThis

iDMUⁱisⁱaⁱshariaⁱbankⁱwithⁱtheⁱlowestⁱaverageⁱefficiencyⁱvalueⁱofⁱ72%ⁱcomparedⁱtoⁱotherⁱDMUs

iobserved.

The ⁱrelatively ⁱsimilar ⁱconditions ⁱare ⁱthose ⁱexperienced ⁱby ⁱBCAS. ⁱBCASⁱBankⁱhas

irelativelyⁱnoⁱsignificantⁱchangesⁱfromⁱ2011-2013ⁱinⁱtheⁱfirstⁱwindowⁱ(withⁱefficiencyⁱvaluesⁱof

i76%,ⁱ72%ⁱandⁱ71%),ⁱaccordingⁱtoⁱ2012-2014ⁱinⁱtheⁱsecondⁱwindowⁱ(withⁱefficiencyⁱvaluesⁱof

i61%,ⁱ64%ⁱandⁱ67%)ⁱalsoⁱbetweenⁱ2013-2015ⁱinⁱtheⁱthirdⁱwindowⁱ(withⁱefficiencyⁱvaluesⁱof

i65%,ⁱ68%ⁱandⁱ71%).ⁱTheⁱBNISⁱexperiencedⁱaⁱslightⁱincreaseⁱinⁱefficiencyⁱvaluesⁱinⁱtheⁱfourth

iwindowⁱofⁱ2014-2016ⁱwithⁱefficiencyⁱvaluesⁱofⁱ79%,ⁱ86%ⁱandⁱ82%.

BasedⁱonⁱtheⁱanalysisⁱofⁱtheⁱDEAⁱwindow,ⁱIslamicⁱcommercialⁱbanksⁱwithⁱtheⁱhighest

iaverageⁱvalueⁱduringⁱtheⁱstudyⁱperiodⁱfromⁱ2011-2016ⁱisⁱPaninⁱBankⁱwithⁱanⁱaverageⁱefficiency

ivalueⁱofⁱ89%.ⁱFurthermore,ⁱBankⁱSyariahⁱBukopinⁱ(BSB)ⁱandⁱBankⁱMuamalatⁱfollowedⁱwithⁱan

iaverageⁱefficiencyⁱvalueⁱofⁱ88%.

Fromⁱtheⁱperspectiveⁱofⁱefficiencyⁱstabilityⁱanalysisⁱthroughⁱseveralⁱsummaryⁱstatistics

isuchⁱasⁱstandardⁱdeviationⁱ(SD),ⁱLongⁱDistanceⁱperⁱWindowⁱ(LDW),ⁱLongⁱDistanceⁱperⁱPeriod

i(LDP)ⁱandⁱLongⁱDistanceⁱperⁱYearⁱ(LDY),ⁱIslamicⁱbanksⁱthatⁱareⁱrelativelyⁱstableⁱareⁱefficiency

ibanks.ⁱBankⁱSyariahⁱMandiriⁱ(BSM)ⁱandⁱBCAⁱSyariah.ⁱBSMⁱhasⁱaⁱstatisticalⁱvalueⁱofⁱ0.02ⁱfor

iSD,ⁱ0.08ⁱforⁱLDY,ⁱ0.15ⁱforⁱLDWⁱandⁱ0.18ⁱforⁱLDP.ⁱMeanwhileⁱBCAⁱSyariahⁱhasⁱaⁱstatistical

ivalueⁱofⁱ0.04ⁱforⁱSD,ⁱ0.09ⁱforⁱLDY,ⁱ0.08ⁱforⁱLDWⁱandⁱ0.17ⁱforⁱLDP.ⁱTheⁱdifferenceⁱis,ⁱifⁱBSM

ihasⁱanⁱaverageⁱefficiencyⁱvalueⁱofⁱ0.83ⁱduringⁱtheⁱobservationⁱperiod,ⁱBCAⁱSyariahⁱonlyⁱhasⁱan

iaverageⁱofⁱ0.75ⁱorⁱlowerⁱthanⁱmostⁱotherⁱIslamicⁱbanks.

Conclusion

TheⁱresultsⁱofⁱtheⁱstudyⁱillustrateⁱtheⁱaverageⁱefficiencyⁱscoreⁱofⁱallⁱIslamicⁱCommercial

iBanksⁱ(BUS)ⁱinⁱIndonesiaⁱincludedⁱinⁱtheⁱobservationsⁱfromⁱ2011-2016ⁱfluctuatingⁱthroughout

itheⁱstudyⁱperiod,ⁱwithⁱanⁱaverageⁱvalueⁱofⁱ63ⁱpercent.ⁱTheⁱtimeⁱdroppedⁱtoⁱ58%ⁱinⁱ2012,ⁱthe

iaverageⁱefficiencyⁱofⁱIslamicⁱbanksⁱwasⁱsmallⁱlittleⁱbyⁱlittleⁱagainⁱhasⁱincreased.ⁱThisⁱcanⁱbe

iexplainedⁱbyⁱaⁱnumberⁱofⁱthings,ⁱstartingⁱfromⁱaⁱfairlyⁱhighⁱlevelⁱofⁱcompetition,ⁱmanagementⁱof

ibank ⁱmanagement, ⁱuntil ⁱmicro ⁱand ⁱmacro ⁱturmoil ⁱoriginating ⁱfrom ⁱwithin ⁱand ⁱoutsideⁱthe

icountryⁱthatⁱaffectsⁱtheⁱlevelⁱofⁱefficiencyⁱofⁱIslamicⁱbanksⁱinⁱIndonesia.ⁱThisⁱresultⁱisⁱslightly

idifferent ⁱfrom ⁱthe ⁱfindings ⁱof ⁱNurfalah ⁱet ⁱal. ⁱ(2018) ⁱwhich ⁱstates ⁱthat ⁱIslamic ⁱbanking ⁱis

irelativelyⁱmoreⁱstableⁱcomparedⁱtoⁱconventionalⁱbankingⁱinⁱfacingⁱbothⁱinternalⁱandⁱexternal

ishock.ⁱ

BasedⁱonⁱtheⁱanalysisⁱofⁱtheⁱDEAⁱwindow,ⁱIslamicⁱcommercialⁱbanksⁱwithⁱtheⁱhighest

iaverageⁱvalueⁱduringⁱtheⁱstudyⁱperiodⁱfromⁱ2011-2016ⁱisⁱPaninⁱBankⁱwithⁱanⁱaverageⁱefficiency

ivalueⁱofⁱ89%.ⁱFurthermore,ⁱBankⁱSyariahⁱBukopinⁱ(BSB)ⁱandⁱBankⁱMuamalatⁱwithⁱanⁱaverage

iefficiencyⁱvalueⁱofⁱ88%.ⁱThisⁱresultⁱisⁱnotⁱmuchⁱdifferentⁱfromⁱtheⁱmeasurementⁱresultsⁱwithⁱthe

istandardⁱCRSⁱapproach.ⁱTheⁱdifferenceⁱisⁱthatⁱtheⁱaverageⁱefficiencyⁱvalueⁱofⁱtheⁱDEAⁱwindow

ianalysisⁱisⁱrelativelyⁱhigherⁱcomparedⁱtoⁱtheⁱresultsⁱofⁱtheⁱstandardⁱCRSⁱmodel.ⁱThisⁱcanⁱbe

iunderstood ⁱbecause ⁱthe ⁱmore ⁱobservations ⁱare ⁱprocessed, ⁱthe ⁱmore ⁱit ⁱwill ⁱproduce ⁱlower

iefficiency ⁱvalues. ⁱThe ⁱstrength ⁱof ⁱthe ⁱDEA ⁱwindow ⁱanalysis ⁱmodel ⁱis ⁱthatⁱitⁱcanⁱmeasure

iefficiencyⁱstabilityⁱthroughⁱseveralⁱmeasurementⁱstatistics.ⁱ

Fromⁱtheⁱperspectiveⁱofⁱefficiencyⁱstabilityⁱanalysisⁱthroughⁱseveralⁱsummaryⁱstatistics

isuchⁱasⁱstandardⁱdeviationⁱ(SD),ⁱLongⁱDistanceⁱperⁱWindowⁱ(LDW),ⁱLongⁱDistanceⁱperⁱPeriod

i(LDP)ⁱandⁱLongⁱDistanceⁱperⁱYearⁱ(LDY),ⁱIslamicⁱbanksⁱthatⁱareⁱrelativelyⁱefficiencyⁱisⁱstable

iareⁱBankⁱSyariahⁱMandiriⁱ(BSM)ⁱandⁱBCAⁱSyariah.

AccordingⁱtoⁱRusydianaⁱ(2016),ⁱthereⁱareⁱseveralⁱfactorsⁱthatⁱhaveⁱbecomeⁱobstaclesⁱto

itheⁱdevelopmentⁱofⁱtheⁱIslamicⁱbankingⁱindustryⁱinⁱIndonesia.ⁱSomeⁱofⁱthemⁱare:ⁱ1)ⁱInadequate

icapitalⁱofⁱShariaⁱBanks;ⁱ2)ⁱWeakⁱunderstandingⁱofⁱpractitionersⁱofⁱIslamicⁱbanks;ⁱ3)ⁱLackⁱof

igovernmentⁱsupportⁱandⁱ4)ⁱTrustⁱ&ⁱpublicⁱinterestⁱinⁱIslamicⁱbanksⁱtendⁱtoⁱbeⁱlowⁱ(Rusydiana,

i2016).ⁱThereforeⁱrelatedⁱpartiesⁱneedⁱimprovementⁱinⁱtermsⁱofⁱcapital,ⁱimprovingⁱtheⁱqualityⁱof

iIslamic ⁱbank ⁱHR, ⁱand ⁱno ⁱless ⁱimportant ⁱis ⁱthe ⁱsupport ⁱof ⁱthe ⁱgovernment ⁱand ⁱrelated

istakeholders.