gis for applied economics · gis for applied economics juan carlos muñoz-mora univeristat pompeu...
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GISforAppliedEconomicsJuanCarlosMuñoz-MoraUniveristatPompeuFabra
Nov2016
Overview
Learningbydoingapproach(½theory/applications-½practice)
Wewillreplicatepublishedpapers,yetwecanconsideruseyourownresearchaspractice
PracticeOption1:AsingleproblemsetattheendOption2:Smalltaskaftereachsession
WhyshouldwecareaboutGISinEconomics?
ItisnotnewconceptinEconomicthought!
[...]ifeconomicsprofessionhasnotablyneglectedit[geography],thisisnotbecauseeconomistshavebeen
uninterestedinthesubject,butbecausetheyhaveregardeditasintractable.
Source: .
So,what'snew?Fujita,M;Krugman,PandVenables,A.,1999
[1]NewamazingGISdatasetsavailableout
thereprovidesaoriginalsourceofvariation
Remotelysensedinformation.(DonaldsonandStoreygard,2016)
accesstoinformationdifficulttoobtainbyothermeansunusuallyhighspatialresolutionwidegeographiccoverage
Otherexamples: , , ,Michalopoulos&Papaioannou( , ), ,amongothers.
(VernonHenderson,J.;Storeygard,A.andWeil,D2012)
Hendersonetal(2012) Pinkovskiy&Sala-i-Martin(2016) Hodler&Raschky(2014)2013 2014 Alesinaetal(2016)
HistoricalMapsrecoveryold(persistent)
characteristics
Digitizedby .Hefoundanegativerelationshipbetweenthenumberofslavesexportedfromacountryandcurrenteconomicperformance.
Thenuseby ,Michalopoulos&Papaioannou( , , ), ,,etc.
Nunn(2008)
Nunn&Wantchekon(2011) 2013 2014 2015 Alsan(2015) Alesinaetal.(2016)
Geo-Codedindividual-leveldatasets
exploringgeographyandlocationasanimportantdimension
→locationpatternsofindustriesinUKOthersexamplesofgeo-codeddatasets:.
(Duranton,D.andOverman,H2005)
LSMS-ISA(WorldBank)->geo-codedhouseholdlevel6Africancountries
[2]GISmayimproveempiricalstrategystronger
reducingtheomitted-variablebias(I)
gatheringmoreinformationfromneighborhood
↑transport→↑housepricesOtherniceexamplesare:(i) sociallearninginthediffusionGhana;(ii)
directandspillovereffectsoflocalstatecapacityinColombia
Gibbons,S.andMachin,S(2005)
Conley&Udry(2010) Acemoglu,D;Garcia-Jimeno,C.andRobinson(2014)
reducingtheomitted-variablebias(II)
buildinginstruments
CurrentAfricanCountries&SlaveTradesInstrumentSlaveExport→distancesfromeachAfricancountrytothelocationswhereslavesweredemanded
Nunn(2008)
NewidentificationstrategiesSpatialRegressionDiscontinuity
CurrentAfricanCountries&SlaveTradesColonialInstitutions(Mita)→currentoutcomes
Dell(2010)
Exogenousunitofanalysis
MontalvoandReynal-Querol(2016)
[3]Providesanewdimensionstogatheringmicro-leveldata
ImproveyourdatacollectionMostcollectiondatasoftwareallowstogatherGPSlocation(e.g.ODKSurvey,
SurveyCTO,CAPI)
CrackingGeo-SpatialDatasets"Geo-spatial"data
Theterms"geo-spatial"referstoinformationthatislocatedontheearth'ssurfaceusingcoordinates.
"Geo-spatial"dataType(e.g.line,area)
Attributes(e.g.temperature,...)HowcanIrepresentthosepoints,lines,andareasonthe
surfaceoftheearth?
Location(e.g.coordinates)
GeodeticLocation
Latitude→north-southdirection,relativetotheequatorLongitude→east-westdirection,relativetoanarbitrarypoint(typicallythelocationoftheRoyalObservatoryinGreenwich-
England)
...yetearthisnotaperfectsphere,itismorelikeanoblatespheroid.
ThemathematicianCarlGausseprovedthatitismathematicallyimpossibletoproject shape(e.g.sphere),ontoaflatplanewithoutintroducingsomesortofdistortion.
R3
Whatshouldwedo?cylindricalconicalazimuthal
...weneedtochooseadistortionthatfitsyourneeds
CylindricalProjections
ItincludetheMercatorProjection,theEqual-AreaCylindricalProjection,andtheUniversalTransverseMercatorProjection.
ConicalProjections
ItincludestheAlbersEqual-Area,theLambertConformalConicProjection,andtheEquidistantProjection.
AzimuthalProjections
ItincludestheGnomonicProjection,theLambertEqual-AreaAzimuthalProjection,andtheOrthographicProjection.
CoordinateSystem(pointdirectlyontheearth'ssurface)
NotProjections
(pointonatwo-dimensionalmapthatrepresentsthesurfaceoftheearth)
UseProjections
UnprojectedCoordinateSystem
→ ( , )x0 y0
ProjectedCoordinateSystem
→ ( , )x0̂ y0̂
..stillsomethingmissingyet,wesaidthattheearthisnotaperfectsphere
Datumisamathematicalmodeloftheearthusedtodescribelocationsontheearth'ssurface.Adatumconsistsofasetofreferencepoints,oftencombinedwithamodeloftheshapeof
theearth.
Mostcommondatum:NAD27,NAD83andWGS84
"Geo-spatial"dataLocation(e.g.coordinates)
Attributes(e.g.temperature,...)HowcanIrepresentthosepoints,lines,andareasonthe
surfaceoftheearth?
Type(e.g.line,area)
VectorData
Point(lat, lon)Linestring Polygons Polygons
Rasterdata(imagesasdata)Geo-locatedmapset
Pixelcharacteristicsasmainattribute
Classified(Remotesensitivedata)
RasterData
RasterData
Polygons
Polygons
Linestring
Point
"Geo-spatial"dataGISdataformat
Gettinggeo-spatialdatasetintoafile(s)
ManyformatsavailableRasterData
DEM,geo-tiff,bandbasedfilesVectorData
Shapelife,Simplefeatures,TIGER/Line,...micro-format(WKT,GeoJSON,...)
Shapefile.shpitcontainsthegeometry(type).shx fixedsize.dbf attributes(database)
Otherfilessuchas:.prj(projections)...Samefilename,yetdifferentextensions
developedbyESRI
GIStools
C,C++andPythonbasedsolutions(objected-oriented
syntaxis)
Source:Lawhead,2013
PointArcGIS
CommercialSoftware
Pre-definedpythonpackage-ArcPy(+Model
Builder)
Memorydemanding;Windowsonly
QGISOpensourcesoftware;easytocreatemapimages;
Pre-definedpythonpackage-PyQGIScompatiblewithanyOS(evenandroid)
Moredifferences
StandalonesolutionsCompletecontroloftheunderlyingalgorithms,data,andexecution(no
blackbox)
Integrationwitotherspythonpackages
Solutionno-softwaredepending(replicationandcollaborations)
GISanalysisbeyondthebottoms
Integrationwithnewhigh-performanceenvironment(i.e.cluster,cloud)
