4.4.3 Iindlela

Ilinga yintoni eyenzekayo. Iindlela isizathu sokuba kwenzeke ngayo.

Iingcamango zesithathu eziphambili zokuhamba ngaphaya kwezilingo ezilula zixhobo . IiNdlela asixelele isizathu okanye indlela unyango babangela isiphumo. Inkqubo yokukhangela iinkqubo ngamanye amaxesha ubizwa ngokuba ukhangelelaniso lweenguqulelo zokungenelela okanye ukulungelelanisa iziguquko . Nangona uvavanyo lukulungele ukuqikelela iziphumo ze-causal, aqhelekanga azilungiselelwe ukubonakalisa iindlela. Uvavanyo lweDividenti lunokusinceda siqonde iindlela ngeendlela ezimbini: (1) zisenza sikwazi ukuqokelela iinkcukacha zenkqubo kwaye (2) zisenza sivavanye unyango oluninzi olunxulumene.

Ngenxa yeendlela ezikhohlisayo ukuchaza ngokusemthethweni (Hedström and Ylikoski 2010) , ndiza kuqala ngomzekelo olula: ii-limes kunye ne-scurvy (Gerber and Green 2012) . Ngenkulungwane yeshumi elinesibhozo, oogqirha babenengqiqo enkulu yokuba xa oomkhombe beza kudla iilmes, abazange bafumane i-scurvy. I-Scurvy isifo esibi, ngoko le nto yayinolwazi olunamandla. Kodwa oogqirha abazange bazi ukuba kutheni ii-limes zithintela i-scurvy. Kwaye kwafika ngo-1932, malunga neminyaka engama-200 kamva, ukuba izazinzulu ziyakwazi ukubonisa ngokuqinisekileyo ukuba i-vitamin C yeso sizathu sokuba i-lime yathintele isithwathwa (Carpenter 1988, 191) . Kule meko, i-vitamin C yindlela eyenziwa ngayo iinqwelo ezikhuselekileyo (umzobo 4.10). Enyanisweni, ukuchonga indlela leyo kubaluleke kakhulu kwisayensi-ininzi yesayensi malunga nokuqonda ukuba kutheni izinto zenzeke. Ukuchonga iinkqubo kubaluleke kakhulu. Emva kokuba siqonda ukuba kutheni unyango lusebenza, sinakho ukuphucula unyango olutsha olusebenza kangcono.

Umzobo 4.10: Imida ikhusela i-scurvy kwaye indlela leyo i-vitamin C.

Ngelishwa, iindlela zokuzihlukanisa zinzima kakhulu. Ngokungafani nama-lime kunye ne-scurvy, kwiimeko ezininzi zentlalo, ukunyanga mhlawumbi kusetyenziswa kwiindlela ezininzi ezidibeneyo. Nangona kunjalo, kwimeko yemimiselo yoluntu kunye nokusetyenziswa kwamandla, abaphandi baye bazama ukuhlukanisa iindlela ngokuqokelela idatha yenkqubo kunye novavanyo olunxulumene novavanyo.

Enye indlela yokuvavanya iindlela ezinokusetyenziswa kukuba kukuqokelela iinkcukacha zenkqubo malunga nendlela unyango oluchaphazela ngayo iindlela ezinokwenzeka. Ngokomzekelo, khumbula ukuba u- Allcott (2011) wabonisa ukuba iiNgxelo zeMandla eKhaya zabangela ukuba abantu banciphise ukusetyenziswa kwabo kombane. Kodwa le ngxelo ingayisebenzisi njani umbane osezantsi? Ziziphi iinkqubo? Kwisifundo esilandelayo, u- Allcott and Rogers (2014) bahlangene nenkampani yamandla ukuba, ngeprogram yesaphulelo, bafumene ulwazi malunga nawuphi na abathengi abaphucula izixhobo zabo kwiimodeli ezisebenzayo. Allcott and Rogers (2014) bafumene ukuba abantu abangaphezulu koko bafumana i-Home Energy Reports bahlaziya izixhobo zabo. Kodwa lo mahluko wawuncinci kangangokuthi inokuthi i-2% kuphela yokunciphisa ukusetyenziswa kwamandla kwimizi ephethwe. Ngamanye amazwi, ukuphuculwa komsebenzi kwakungeyona ndlela ebaluleke kakhulu apho i-Home Energy Report iyanciphisa ukusetyenziswa kombane.

Indlela yesibini yokufunda iindlela kukuqhuba iimvavanyo kunye neenguqu ezahlukeneyo zonyango. Umzekelo, ekuhlolweni Schultz et al. (2007) kunye nazo zonke iimvavanyo zengxelo ye-Home Energy Report, abathathi-nxaxheba banikezelwa unyango oluneengxenye ezibalulekileyo (1) iingcebiso malunga nokugcinwa kwamandla kunye (2) nolwazi malunga nokusetyenziswa kwamandla kunye noontanga (umfanekiso 4.6). Ngaloo ndlela, kunokwenzeka ukuba iingcebiso zokulondoloza amandla zibangelwa utshintsho, kungekhona ulwazi lontanga. Ukuvavanya ukuba kungenzeka ukuba iingcebiso zodwa zanele, Ferraro, Miranda, and Price (2011) ihlangene nenkampani yamanzi kufuphi nase-Atlanta, eGeorgia, kwaye yaqhuba umlinganiselo onxulumene nokugcinwa kwamanzi okubandakanya imizi engama-100 000. Kwakuneemeko ezine:

• iqela elifumene iingcebiso ekulondolozeni amanzi
• iqela elifumene iingcebiso ekulondolozeni amanzi kunye nesibheno sokuziphatha sokugcina amanzi
• iqela elifumene iingcebiso ekulondolozeni amanzi kunye nesibheno sokuziphatha ukugcina amanzi kunye nolwazi malunga nokusetyenziswa kwamanzi malunga neontanga zabo
• iqela lolawulo

Abaphandi bafumanisa ukuba unyango-kuphela lonyango aluzange lube nempembelelo ekusebenziseni kwamanzi ngexesha elifutshane (omnye unyaka), eliphakathi (iminyaka emibini), kunye nexesha elide (iminyaka emithathu). Iingcebiso kunye nokunyangwa kwesibheno kwabangela ukuba abathathi-nxaxheba banciphise ukusetyenziswa kwamanzi, kodwa kuphela kwixesha elifutshane. Ekugqibeleni, iingcebiso kunye nesibheno kunye nolwaphulo lonyango lwabafundi lubangela ukusetyenziswa kwehla kwithuba elifutshane, eliphakathi nelide (umzekeliso 4.11). Ezi zinzame zokuzama ukufumana unyango olungenakunikwa yindlela efanelekileyo yokufumanisa ukuba yiyiphi inxalenye yonyango-okanye nayiphi iindawo ezidibeneyo-ezibangelwa umphumo (Gerber and Green 2012, sec. 10.6) . Ngokomzekelo, ukuzama kukaFerraro kunye noogxa bethu kubonisa ukuba iingcebiso zokugcina amanzi kuphela azikwanele ukunciphisa ukusetyenziswa kwamanzi.

Umzobo 4.11: Iziphumo ezivela Ferraro, Miranda, and Price (2011) . Unyango lwathunyelwa ngoMeyi 21, ngo-2007, kwaye iziphumo zacatshulwa ngethuba lokusasaza ngo-2007, ngo-2008, no-2009. Ngokungahambanga unyango, abaphandi bafuna ukuphucula ingqondo engcono yezixhobo. Ipropati-kuphela yonyango yayingenasiphumo esifutshane (unyaka omnye), phakathi (iminyaka emibini), kunye nexesha elide (iminyaka emithathu). Iingcebiso kunye nokunyangwa kwesibheno kwabangela ukuba abathathi-nxaxheba banciphise ukusetyenziswa kwamanzi, kodwa kwithuba elifutshane. Iingcebiso kunye nesibheno kunye nolwaphulo lonyango lubangele ukuba abathathi-nxaxheba banciphise ukusetyenziswa kwamanzi ngexesha elifutshane, eliphakathi nelide. Imivalo ye-vertical iqikelelwe ukuzithemba. Jonga Bernedo, Ferraro, and Price (2014) malunga nezixhobo zokufunda. Ukutshintshwa Ferraro, Miranda, and Price (2011) , itafile 1.

Ngokufanelekileyo, omnye uya kudlulela ngaphaya kokubekwa kwamacandelo (iingcebiso; iingcebiso kunye nesibheno; iingcebiso kunye nesibheno kunye nolwazi lwontanga) kwi-designory epheleleyo-ngamanye amaxesha kuthiwa yi \(2^k\) Iimpawu ezintathu zivavanywa (itheyibhile 4.1). Ngokuvavanya yonke into enokubambisana yamacandelo, abaphandi bavavanya ngokupheleleyo umphumo wecandelo ngalinye kwedwa kunye kunye kunye. Ngokomzekelo, ukulinga kukaFerraro kunye noogxa abachazi ukuba ngaba ithelekiso yontanga yodwa yayiya kubakho ukukhokelela ekutshintsheni kwexesha elide ekuziphatheni. Kwixesha elidlulileyo, ezi zinto zenzeke nzima ukuqhuba ngenxa yokuba zifuna inani elikhulu labathathi-nxaxheba kwaye zidinga ukuba uphandi bakwazi ukulawula ngokuchanekileyo kunye nokuhambisa inani elikhulu lonyango. Kodwa, kwezinye iimeko, i-digital age iyakususa le miqobo.

Isishwankathelo, iinkqubo-iindlela ezonyango oluchaphazela ngayo-zibaluleke kakhulu. Uvavanyo lweeminyaka yobudala lunokunceda abaphandi bafunde malunga neendlela (1) zokuqokelela idatha yenkqubo kunye (2) nokunika izixhobo zokwenza izinto ezipheleleyo. Iinkqubo eziphakanyiswe ezi ndlela ziza kuvavanywa ngokuzodwa ngolu vavanyo olwenzelwe ukuhlola iindlela (Ludwig, Kling, and Mullainathan 2011; Imai, Tingley, and Yamamoto 2013; Pirlott and MacKinnon 2016) .

Ngokwezizonke, ezi ngongoma ezintathu-ukuqinisekiswa, i-heterogeneity yeempembelelo zonyango, kunye neendlela-zinika iinjongo ezinamandla zokwenza nokutolika iimvavanyo. Ezi ngcamango zinceda abaphandi baqhube ngaphaya kwezilingo ezilula malunga nento "esebenzayo" ekucebiseni okucebileyo okunxibelelwano oluqinileyo kwimbono, ebonisa ukuba kuphi na ukuba kutheni ukunyanga, kwaye oko kunokubanceda abaphandi baqulunqe unyango olululo. Njengoko le mvelaphi yolwazi malunga nokulinga, ngoku ndiya kuphendukela kwindlela onokuyenza ngayo okokuvavanya kwakho.