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Policy
Research
Working
Paper10683e
Welf
are
C
ost
of
D
rou
ghtin
Sub-Saharan
AfricaJon
GascoigneSandra
BaquieKatja
VinhaEmmanuelSkou?asEvie
CalcuttVarun
KshirsagarConorMeenanRuthHillPov
ert
yand
Equity
Global
PracticeJanu
ary
2024Policy
Research
Working
Paper
10683Abstractis
p
ap
er
quanti?es
the
imp
act
of
d
rou
ght
on
householdconsumption
for
?ve
main
agroecological
z
ones
in
A
f
rica,develop
ing
vulnerability
(or
damage)
functions
of
therelat
ionship
between
rainfall
de?cits
and
p
overty.
Damagefunctions
a
re
a
key
elem
ent
in
models
that
quantify
therisk
of
extreme
weatherand
the
imp
acts
of
climate
change.A
lthou
gh
these
functions
are
com
m
only
estimated
forst
orm
or
?ood
damages
tobuildings,
they
are
less
oftenavailab
le
for
income
losses
f
rom
d
rou
ght
s.e
p
ap
er
takesa
regionalap
p
roach
to
the
analysis,
develop
ing
standardizedhaz
ard
de?nitions
and
methods
for
matching
haz
ard
andhousehold
data,
allowing
survey
data
from
close
to
100,000hou
sehold
s
tobe
used
in
the
analy
sis.
e
damage
func-tions
are
used
to
quantify
the
imp
act
of
historical
weatherconditionson
p
overty
for
eight
countries,
highlighting
therisk
to
p
overty
outcomes
that
weather
variability
causes.National
p
overty
rat
es
are
1–12
p
ercent
hi
gher,
dependingon
the
country,
underthe
worst
weather
conditions
relativeto
the
best
conditions
observed
in
the
p
ast
13
y
ears.
isamounts
to
an
increase
in
the
total
p
overty
gap
that
rangesf
rom
US$4
m
illion
toUS$2.4
b
illion
(2011
p
urchasingp
ower
p
arity).is
paper
is
a
p
roduct
of
the
Pov
ert
y
and
Equity
Global
Practice.
It
is
p
art
of
a
larger
e?
ort
by
the
World
Bank
top
rovide
op
en
access
to
its
research
and
make
a
contributionto
develop
ment
p
olicy
discussions
arou
nd
the
w
orld
.
Poli
cyResearch
Working
Pap
ers
a
re
also
p
osted
on
the
Web
at
http
:///p
rwp
.e
au
t
hors
may
be
contactedat
rhill@
w
orld
b
ank.
org.e
Policy
Research
Working
Paper
Series
disseminates
the
?ndings
of
work
in
progress
to
encourage
the
exchange
of
ideas
about
developmentissues.
An
objective
of
the
series
is
to
get
the
?ndings
out
quickly,
even
if
the
presentations
are
less
than
fully
polished.
e
papers
carry
thenames
of
the
authors
and
should
be
cited
accordingly.
e
?ndings,
interpretations,
and
conclusions
expressed
in
this
paper
are
entirely
thoseoftheauthors.eydonotnecessarilyrepresenttheviewsoftheInternationalBankforReconstructionandDevelopment/WorldBankanditsa?liatedorganizations,orthoseoftheExecutiveDirectorsofthe
World
Bankorthegovernmentstheyrepresent.ProducedbytheResearchSupport
TeamThe
Welfare
Cost
of
Drought
in
Sub-Saharan
AfricaJonGascoigne(Centre
forDisasterProtection)?
SandraBaquie(WorldBank)?
KatjaVinha(Consultant)?
EmmanuelSkoufias(NationalUniversityof
SingaporeandWorldBank)?
EvieCalcutt(WorldBank)?
VarunKshirsagarConsultant)?
ConorMeenan(Centre
forDisasterProtection)?
RuthHill(WorldBankandCentreforDisasterProtection)1JELCodes:Q54,I32ProjectCode:P177432Keywords/topics:Shocksandvulnerabilitytopoverty,drought1
?indicates
randomizedauthororderusingtheAmericanEconomicAssociationauthor
randomizationtool,/journals/policies/random-author-order/search?RandomAuthorsSearch%5Bsearch%5D=XxSZtJmQOh5k.ThispaperstartedasaresultofaconversationwithJonGascoigneinearly2020.Jon
understoodbetterthananyofustheneedforamultidisciplinaryteamtounderstandhowtomodelthewelfareimpactsofdrought.Collaboratingacrossdisciplinescanbeachallenge,andnegotiatingthosediscussionsrequiresgoodgrace,humility,astrongfocusonrelationship,andagenuineinterestinunderstandinganother’sviewandexpertise.Jonexemplifiedthesecharacteristicsinallofhiswork,andtruetoform,broughtthemtothisprojecttoo.Wethinkitisveryfittingthattherandomizationtoolplacedhimasfirstauthoronthispaperearlyinitsdrafting.Wearesaddenedhedidn’tgetto
seethefinalproductandto
knowjusthowgratefulweall
weretohimandtheexamplehesetus.WethankStefanieBrunelinandOdyssiaNgforbeingpartoftheearlyconversationonthispaperandwethankBhavinThakrarandPaulWilsonforworkingonpartsofthe
simulationsdataexercise.1.
IntroductionClimatedisastersreversegainsandlimitprogressineffortstoreducepoverty.GlobalextremepovertyisincreasinglyconcentratedinSub-SaharanAfrica(SSA)wheredroughtisamajorrisk,ariskthatisincreasinginmanypartsofthecontinentbecauseofclimatechange.Investmentstoreducetheimpactofdroughtonwelfarearethusessentialtopovertyreductioneffortsintheregion.
Quantifyingthewelfareneedsthatarisewhenclimateshocksoccurisanimportantpartoftargetinginvestmentstoreducetheirimpact(ClarkeandDercon2016).
Thisrequiresvulnerabilityordamagefunctionsthatrelatelossesinwelfaretoclimateconditions(Auffhammer2018).Whilethesearewidelyavailablefortheimpactoffloodsandcyclonesonbuildings,thisisnotthecasewhenitcomestoquantifyingtheimpactofdroughtonhouseholdconsumptioninSub-SaharanAfrica.Thispaperpilotsaregionalapproachtoestimatingvulnerabilityfunctionsfordroughtandconsumptionusingmethodswidelyemployedinthemicroeconomicliterature(Dell,Jones,andOlken2014).
Theanalysisusessurveydatafromcloseto100,000householdsacrossninecountriesandfivelivelihood
zones,allowingconsiderablevariationinclimaticconditionstobeutilizedinestimation.
Theresultisstableestimatesthatarenotdrivenby
anyoneclimate
event.Wefindthatconsumptionisreducedby
10-20percentintheworstweatherobservationsinoursurveys(correspondingto
abouta1in10-yeardroughtevent).Weusetheestimatedvulnerability
functionsandthefullhazarddistributionineachhouseholdlocationtocalculatetheriskdroughtposestowelfareoutcomes.
Theresultsindicatethatriskislarge.Povertyis1–12percenthigherundertheworstweather
conditionsrelativetothebestconditionsobservedinthepast13years.ThisamountstoanincreaseinthetotalnationalpovertygapthatrangesfromUS$4milliontoUS$2.4billion(2011PPP)acrosscountries.To
ourknowledge,thesearethefirstcross-countryestimatesofthepovertyimpactofdroughtinAfrica.There
are
several
ways
in
which
damage
functions
for
rainfall
deficits
have
been
estimated
in
the
climate
economicsliterature.
Auffhammer
(2018)
provides
a
reviewand
examples
oftheapproaches
applied
to
US
farmincomes.
Theone
used
for
estimating
the
impact
of
extreme
weather
events
uses
observed
data
to
identify
the
causal
impact
ofweatherchangesonoutcomesofinterest(Dell,Jones,and
Olken2014).Dataonhazards
arematchedtohouseholdobservations
in
survey
data
using
information
on
the
geographic
location
of
a
household,
and
a
fixed
effectsregressionisruntoidentifytheimpactofweatherindeterminingeconomicoutcomes.Although
not
undertaken
with
the
purpose
of
estimating
vulnerability
functions,
several
studies
have
used
thismethod
to
estimate
the
impact
of
drought
on
welfare.
For
example,
in
Africa,
Hill
and
Porter
(2017)
look
at
theimpact
of
a
water
requirement
satisfaction
index
(WRSI)
on
consumption
and
poverty,
and
Hill
and
Mejia-Mantilla(2017)
look
at
the
impact
of
WRSI
on
household
income
and
consumption
in
Uganda.
In
Malawi,
Baquie
and
Fuje(2020)
look
at
the
impact
of
rainfall
on
consumption
and
poverty.
Wineman,
Mason,
Ochieng
and
Kirimi
(2019)examine
therelationship
between
rainfall
and
income,
calorieconsumption
and
poverty
in
Kenya.
Baez,
Kshirsagarand
Skoufias
(2019)
look
at
the
impact
of
rainfall
defined
dry
spells
on
nutrition
outcomes.
Outside
Africa,
Kochharand
Knippenberg
(2023)
look
at
the
impact
of
NDVI,
rainfall
and
temperature
on
consumption
and
poverty
inAfghanistan.
Studies
that
use
estimated
impacts
of
drought
to
predict
the
welfare
cost
of
other
weather
eventsincludeHillandPorter(2017),
PorterandWhite(2016),KochharandKnippenberg(2023).2Thisstudyusesthe
samemethodsas
thesepapersbuttakes
aregionalapproach(asinBaez,KshirsagarandSkoufias2019)withtheobjectiveofdevelopingrobustestimatesoftherelationshipbetweendroughtconditionsandconsumptionthatisnotspecifictoonecontextor
event.Thisrelationshipcanthenbeusedtopredicttheimpactofdroughtforothereventsorlocations.Theestimatespresentedinthispaperarewithintherangeofresultsfoundincountry-specificpapers.Forexample,amoderate(abouta1in10year)droughtispredictedtoreduceconsumptionby15percentand9percentinUgandaandEthiopia,akinto
the10percentlossweestimateforcropcultivatinghouseholdsinmaizeandhighlandzonesinthispaper.2Anttila-HughesandSharma(2015)takethesameapproachforstorms.2Takingaregionalapproachrequirestheuseofstandardizedhazarddefinitionsandmethodsformatchinghazardandhouseholddata.Thisisdonebyconsideringthemainhazardmeasuresandtechniquesusedincomparablecountrystudies,andsystematicallyassessingthechoiceofhazard,thehazard-householdmatchingapproach,andthefunctionalformusedinanalysis.Specifically,weusegriddedhistoricaldataonprecipitation,vegetation,evapotranspiration,andsoil
moisture,usingmeasuressuchastheNormalizedDifferenceVegetationIndex(NDVI),theStandardizedPrecipitationEvapotranspirationIndex(SPEI),andWRSI.Thesemeasuresreflectthehazardtolivelihoodsfromlackofrainindifferentways.Somearedirectmeasuresofclimateconditions(e.g.,precipitation,soilmoisture,andSPEI),othersaggregateclimatedatathroughcropmodels(WRSI),andothersmeasurevegetationoutcomes(NDVI).Thegriddedhazardmeasuresarethenmergedtoharmonizedhouseholdsurveysfromninecountries
(Ethiopia,Lesotho,Malawi,Mauritania,Mozambique,Niger,Nigeria,
Zambia,andZimbabwe)withlocationcoordinatesforeitherthehouseholdorthecommunity.Thesurveysusedaretheonesthatarealsousedforofficialpovertyestimates.Aconsistentapproachto
temporalmatchingwasusedtotakeintoaccountthetimingofthesurveyandagriculturalseasons.Differentapproachestospatial
mergingweretested.Thereareimportantmethodologicalinsightsfromtheanalysisthatemerge.
First,we
findthatsoilmoistureandgreennessmeasuresprovidemoreconsistentlyreliableresultsthanevapotranspirationorrainfallmeasures.Thisisanimportantfindinggivenmostoftheextantliteratureisbasedonevapotranspirationorrainfallmetrics.Second,wefindthatalinearspecificationperformsadequatelyforthetypesofmoderateshocksthatarewell-representedinthesurveydataused.Third,wefindthatahazardmeasurebasedon20kmor50kmradiusaroundeachhouseholdperformsbetterthanthosethat
usesmallerradii,perhapsbecausealargerradiusallows
localmarketeffectstoalsobeconsidered.Therelationshipbetweenhazardmeasuresandwelfareoutcomesisestimatedseparately
fordifferentlivelihoodzonesacrossSSA.Separateestimationprovidesneededflexibility,giventhatdroughtconditionsmanifestthemselvesdifferentlyacrosslivelihoodzones.Importantdifferencesinimpactsbetween
agroecologicalzonesandbetweenlandandlivestockowners
areobserved.However,thedownsideofaregionalapproachisalimitedabilitytoexploretheheterogeneity
ofimpactsacrosshouseholdsindetailwithoutsignificantinvestmentsindataharmonization,andweleaveadditionalworkontheheterogeneityofimpacts
assomethingtoexplorefurtherinfutureanalysis.Therearelimitationstotheanalysisundertakenthat
shouldbeborneinmindwheninterpretingresults.First,estimates
capturethedirectimpactoflocaldroughtconditionsandnot
impactsbeyondthelocalarea,suchasthosethatmightarisefromdisruptionofmarketsorpriceimpacts.Thedegreetowhich
thisisaconcerndependsontherelativeimportanceofdirectandindirectimpacts.Theevidenceismixedonthis.Hallegatteetal.(2016)suggestfoodpricesareanimportantchannelofthewelfareimpactsofclimatechange.
However,Artucetal.(2023)
modeltradebetweenlocations
andfindthemainimpactisthedirectproductioneffect,nottheimpactonprices.To
theextentthisisthecasethelocalestimatespresentedinthispapermay
bequiteclosetoaggregateimpacts.Secondly,theempirical
estimatesaresubjectto“survivorbias”
inthat
consumptionisonlymeasuredforhouseholdsstillinexistenceaftertheshockhasoccurred.Ifhouseholdsmoveordisintegrate(perhapsduetothedeathofoneormorehouseholdmembers)becauseofdroughtconditions,theestimatedimpactscouldbe
overorunderestimated.Thisismuchmorelikelytobethecaseforseveredroughtconditions,whereas
thosethatarecapturedinoursurveystendto
belessextremeeventsthat
areunlikelytocausemovementordisintegrationofhouseholds.Thisbringsusto
thethirdpotentialsourceofbiasintheresults.Althoughtheanalysisuses
surveydata
acrossmanyweatherconditionsintheanalysis,
thereareveryfewobservationsinthesurveydatathatexperiencedroughtconditionsbelowtwo
standarddeviationsfromthe
mean.Thislimitsthedegreeto
whichnon-linearitiescanbeestimated.Italsomeansthereislimitedempiricalsupportforpredictingthewelfarecostsofextremeevents.Afinalsourceofbiascomes
frommeasurementerrorin
thehazarddata.
Althoughcarewastakentousethebestavailabledataandmatchhazardandhouseholddata
carefully,anymeasurementerrorinthehazardvariablewillattenuatetheestimatedcoefficients,therebyunderestimatingthewelfareimpacts.Additionaluncertaintyis3presentgiventhedistributionofhazardsischangingovertimewithclimate
changeandhistoricaldataformsthebasisofallsimulationspresentedin
thispaper.Themodelsbuiltinthispaperareanimportantfirststeptowardconstructingvulnerabilityordamagefunctionsasusedinthecatastropheriskmodelingliterature,andcaninformdisasterresponseplanningandfinancing.However,theselimitationsmeanthatcareisneededininterpretingtheresultsoftheanalysis.Weenvisagethatthesetoftoolsdevelopedhereinwillprovidethebasisforrefiningtheanalysisasmoredatabecomeavailable,andexpandingcoveragetootherregions.Accompanyingthispaperiscodedesignedtoextractalargesetofpotentialshockmeasuresanddeterminewhichoftheseareconsistentwithchangesinthewelfaremeasures(out-of-sample).The
modularcodeusedisintendedto
betransparent,toaidinreplicability,andtobeavailableforotherstoimproveupon.Thegoalistoencouragebothlearningandcommonstandards,whichinturncontributetotheimplementationofdrought-responsivepoliciesthat
areobjectiveandtransparent.Thepaperisstructuredasfollows.Section2presentstheempiricalframeworkforassessingtherelationshipbetweenwelfareandhazardsinruralareaswhererainfall-dependentagriculturalproductionisdominant,andwhererainfalldeficits(droughts)thusmayhaveveryseriouswelfare
consequences.Itsetsouttheapproachusedtoestimatethevulnerabilityfunctionandan
exceedanceprobabilitycurvethat
describesthewelfarelosseslikelytooccurbecauseofrainfalldeficitsofincreasingseverity.
Section3discussesindetailthehistoricalhazarddatabaseandthehouseholdsurveydataused,themergingofthehazarddatato
thehouseholdsurveydata,andthespecificationsusedforthehazardmeasures.Section4presentsestimatesofvulnerabilityfunctions.Section5showshowthesevulnerabilityfunctionscanbeusedtoprojectwelfarelossesandpresentssomeexceedanceprobabilitycurves.Section6offers
someconclusions.2.
An
EmpiricalFrameworkfor
an
Ex
AnteAssessmentoftheWelfareCostsofDroughtAcatastropheriskmodelingframeworkusesthreecomponentstogenerateanex
anteassessmentofthecostsofacatastrophe:hazard,exposure,andvulnerabilityfunction.
Hazardscapturedata
onthepossibleweatheroutcomesthatmayoccurina
givenplace,suchaspossibletropicalcyclones.Exposurecaptureswhatcouldbeaffectedbythehazardinthatlocation,suchas
thenumberandtypeofbuildings.A
vulnerabilityfunctionprovidesanestimateofthecostofdamagethatwilloccurasaresultofagivenhazardandagivenexposure.Intheexampleoftropicalcyclonesandbuildings,itwouldindicatethecostofdamageforagiven
windspeedaffectingagiventypeofbuilding.Combiningthethreecomponentsallows
developmentofaprobabilisticimpactcurve,whichindicates
howthecostofhazardvarieswiththeprobabilityofthehazardforaspecificplace,giventheexpectedhazardsandtheexposedassets.Thissectionofthepapershows
howthisframeworkcanbe
appliedtogenerateaprobabilisticimpactcurvefordroughtinSSA.FordroughtinSSA,thehazardisrainfalldeficitsduringthegrowingseason.Asnotedintheintroduction,therearedifferentwaysofmeasuringthis
hazard,andthenextsectiondiscussestherelevantdata
inmoredetail,includingthetimeperiodforwhichhistoricaldataareavailableanduseofthedatatogenerateanestimateoftheprobabilitydistributionofhazardsinthenearfuture.Exposureinthecurrentcaseis
notaboutphysicalinfrastructureanditslocationandcharacteristics,butabouthouseholdsthatmaybeimpacteddifferentlybyrainfalldeficitsdependingontheirlocationandcharacteristics.Thedataonhouseholdsarealsodescribedinmoredetailinthenextsection.Thevulnerabilityfunctioninthiscaseistheincomeorwelfarelossesamong
households
engagedindifferentlivelihoods,whichresultfromloweryields,lowerdemandforlabor,andincreased
pricesthatmayresultfromthat.Therestofthissectionfocusesontheestimationofthevulnerabilityfunctionandhowit
isusedtoderiveaprobabilisticimpactcurve.Theestimationofthevulnerabilityfunctioniswidelypresentinthemicroeconometricliterature,eventhoughitisnotreferredtoassuchor
used
forgenerating
estimatesofprobabilisticimpact.42.1.
EstimatingavulnerabilityfunctionHouseholdwelfareatanygiventimemaybesummarizedingeneralbythefunction
below:=(,,)
+
,?(1)denotesthemeasureofwelfare(inthecurrentanalysis,logofpercapitaexpenditureshousehold?
inlocalityorcluster
,),
isthemeasureofthehazardattime
atthelevelofthegeographiccluster
denoteshouseholdobservablecharacteristics,
denotesanobservablevariablesummarizingtheenvironmentofhouseholds,and???whereof??,??isanerrortermsummarizingtheinfluenceofallunobservablefactorson?welfare.3Forthepurposesofthis
study,welfareismeasuredbythemonetaryvalueoftotalconsumptionexpendituresorfoodandnon-foodconsumption.4Themainobjectiveof
avulnerabilityfunctionisto
summarizetherelationshipbetweenthe
levelof
andthelevelof
.Ifthefunction
were
knownaprioriitwouldbesimpletopluginvaluesfor,,and
todeterminethevalueofthewelfareoutcome
.Intheabsenceofinformationonthefunction
,methodsneedtobeemployedtoestimateit.Thisnecessitygivesrisetoafundamentaltrade-offbetweenthepredictionaccuracyandtheinterpretabilityofthemodelused(Jamesetal.2013).Forexample,machinelearningmethods,suchas
random
forests,bagging,boosting,andsupportvector
machines,treat
asablackbox.Noneofthesemethodsisespeciallyconcernedabouttheexactformandinterpretabilityofthefunction
,providedthatityieldsaccuratepredictionsforthewelfareoutcome.Ontheotherhand,approximatingthefunction
withtheaveragevalueofthewelfareoutcomeonspecificvaluesoftheexplanatoryvariables
,and
—i.e.,
(
,
,
)
=conditional?,,(|==1????),
ortheconditionalexpectedfunction(CEF)—is
typicallyeasiertointerpretandisusefulfordeeper,=?insightsintothecausalrelationshipbetweenhazardandwelfare(AngristandPischke2009).Theseadvantages,however,maycomeattheexpenseofpredictiveaccuracy(in-sampleorout-of-sample).5Withtheseconsiderationsinmind,weadopttheCEFapproachforestimatingvulnerabilityfunctions.To
keeptheanalysissimpleandtractable,theapproachbeginswithanad
hocspecificationofthecontrolsusedintheregressionmodel,usingalinearapproximationtotheCEFthatisextendedtoanonlinear
specificationforthehazardandallowingforthepotentialheterogeneityofthehazard’simpactson
welfarebasedonsomeeasilyandcommonlyobservablehouseholdcharacteristicsandenvironmentalfeatures.Foranygivenwelfaremeasure
?,aloglinearapproximationtoequation(1)aboveyields=++++++,?(2)?01?21?where
denotesregion-ordistrict-levelfixedeffectsand
denotescountry-surveyyeareffects.Thedistrict-levelfixedeffectscontrolforfixedspatialcharacteristics,whetherobservedorunobserved,andthusdisentanglethehazardmeasurefrommanypossiblesourcesofomittedvariablebias.Theyeareffects
furthercontrolforanycommontrendsandthushelpensurethattherelationshipsofinterestareidentified
fromidiosyncraticlocalX3
Theelementsof
canincludetheageandeducationlevel
ofthehouseholdhead;theethnicity,religion,totalnumber,age,andgendercompositionofhouseholdmembers;ownershipofassetssuchas
livestock,phone,radio,TV,
etc.;andcharacteristicsofthehouseholdresidence,includingtypeandqualityofwaterandsanitationfacilities,mainsourceofenergy,andtypeoffloorandmaterialofconstructionforwallsandroof.4Focusingonnon-monetarydimensionsofwelfaresuchastheheightforagezscoreofchildren
(HAZ)ortheweightforheightz-score(WHZ),Skoufiasetal.(2023)
exploreanalternativespecification
ofthevulnerabilityfunctionthatallowsconsiderationoftheeffectsofhazardsthroughtheincomeaswellastheenvironmentalchannels.Inthisspecification,exposuretoweather-related
hazardsmayaffectthevalueofagriculturalincomeearned(theincomechannel),
aswellasthehealthstatusof
householdmembers
(environmentalchannel).5Indata-constrainedenvironmentsliketheoneswestudy,complex(black-box)machinelearningmodelsareunlikelytoprovidethegainsin
accuracythatjustifythelossininterpretability.5shocks.Thustheempiricalapproachisverymuchinlinewiththestrongidentificationpropertiesoftheweather-shockapproachsummarizedbyDell,Jones,andOlken(2014).Itshouldbenotedthatwithdistrictfixedeffects,,includedinthespecification,thecoefficients
canbeestimatedonlyifthevaluesofOtherwise,theuseofthedistrictdummies
willabsorbtheeffectsoftheseenvironmentalfactors.varywithindistricts.1?Theimpactofdroughtonconsumptionexpendituresisthe
cumulativeeffectof
ahousehold’scroploss
andaseriesofentitlementfailuresinalocaleconomythataretriggeredbythisinitialloss(Sen,1981;Deveraux,2007).Devereux(2007)characterizesasequenceoffourentitlementfailures:first,productionfailsasaresultoftherainsfailing;thenlabormarketsfail
ashouseholdsarelessandlessabletofindworkopportunitiesonotherfarmsorinoff-farmactivities;thencommoditymarketsfailasgrainpricesincreaseandpricesofliquidassetsdecrease.Finally,transfersfailashouseholdscannotrelyon
thesupportofothersintheirnetworkwhoface
thesameconstraintsinmeetingeverydaybasicneeds.Theformulationoutlinedhereisagnosticas
tohowrainfallisimpactingconsumption.However,thespatialmeasureofdroughtusedand
thenecessityofincorporatingdistrictfixedeffectsfocusestheanalysismoreonpickingupproductionfailuresandfailuresintheimmediatelaborandcommoditylocalmarketinwhichthedroughtismeasured.
Theimpactofdroughtthroughcommoditymarketsthatspanalargergeographicareaortransfernetworksoveralargergeographicspacewillnotbepickedup.Ifhigherlevelsofindicaterainfallsufficiency,itisanticipatedthat
?
>
0suchthatlackofrainfalland2droughtshaveanegativeeffectonwelfare(especiallywhenamonetarywelfaremeasureisused,suchasconsumptionexpendituresperadultequivalent).Theextenttowhichhazardsexperiencedbyhouseholdsinthesampleareassociatedwithsufficientlysignificantdeclinesintheirwelfaredependsinpartonthedegreetowhichthereisvariabilityintheexposuretoandintensityoftheshocksexperienced.Forexample,if
thevalueofwithinagivencluster,thenthereisnowaytoidentifytheparameter
2.Hence,itiscritical
toderiveestimatesof?
basedondatathatincludesignificantvariabilityin
.Thistaskisa
particularchallengewhenanalyzingtheimpactofdroughtbecausetheseeventsarespatiallycorrelatedandnotlocalized.Increasingthenumberofyearsa
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