2.4.3.1 imifuniselo Natural
Imifuniselo Natural ukusebenzisa iziganeko nandawoni ehlabathini. yintlekele + usoloko-kwindlela data = ukucikideka yendalo
Undoqo olungenamkhethe imifuniselo elawulwayo evumela uthelekiso fair ke engakhethiyo. Kodwa, ngamanye amaxesha into eyenzekayo ehlabathini ukuba okunemfuneko unika abantu ngokungakhethiyo okanye phantse randomly zonyango ezahlukeneyo. Enye imizekelo zicacileyo yesicwangciso kusetyenziswa imifuniselo yendalo iphuma uphando Angrist (1990) ukuba ilinganisela ifuthe iinkonzo umkhosi ngemivuzo.
Ngexesha lemfazwe eVietnam, eUnited States ukwanda ubukhulu imikhosi yayo exhobileyo ngokusebenzisa uyilo. Ukuze isigqibo apho abemi baya kubizwa kwinkonzo, urhulumente US yabamba ilotto. Wonke wokuzalwa yayimelwe kwi ephepheni, kwaye ezi amaphepha babekwa nengqayi enkulu iglasi. Njengoko kubonisiwe kumfanekiso 2.5, ezi njengezithole iphepha athatyathwe ingqayi enye ngexesha ukumisela umyalelo ukuba abafana uya kubizwa ukuze bakhonze (abafazi abaselula zichatshazelwe idrafti). Ngokusekelwe kwiziphumo, azalelwe ngoSeptemba 14 kuqala babebizwa, azalelwe ngoAprili 24 babebizwa yesibini, njalo-njalo. Ekugqibeleni, oku lotto, azalelwe ngeentsuku ezahlukeneyo 195 enabizelwa kwinkonzo xa azalelwe ngeentsuku 171 hayi babebizwa.
Isazobe 2.5: Congressman Alexander Pirnie (R-NY) ngokuzoba kwisingxobo lokuqala uyilo kukhetha Service ngoDisemba 1, 1969. UYoshuwa Angrist (1990) zidibene uyilo Iloyo data ingeniso evela Administration Security Social ukuqikelela isiphumo emkhosini ngemivuzo. Lo ngumzekelo uphando usebenzisa lamava yendalo. Umthombo: Wikimedia Commons
Nakuba asenokungacaci kwangoku, idrafti leloto kukho ukufana kakhulu kwelinge alawulwayo: kuzo zombini iimeko nxaxheba ngokungenamkhethe kufumana unyango. Kwimeko idrafti leloto, ukuba nomdla wokufunda iziphumo uyilo-ukufaneleka kunye emkhosini ngemivuzo kwimarike yemisebenzi elandelayo, sinako ukuthelekisa iziphumo abantu Birthdates bawo ngezantsi ukufakelelwa leloto (umzekelo, September 14, Aprili 24, njalo njalo) kunye neziphumo abantu yokuzalwa bakhe emva ukufakelelwa (umzekelo, Februwari 20, ngoDisemba 2, njalo njalo).
Njengoko olu nyango yokuba sayilwa sele ngokungenamkhethe, siya ukulinganisa ifuthe le nonyango lwazo naziphi na isiphumo ukuba sele kulinganiswa. Umzekelo, Angrist (1990) ezidityanisiweyo ulwazi malunga lowo randomly Kukhethwe uyilo kunye data imivuzo ethe yaqokelelwa Administration Security Social bagqibe ukuba ngengeniso amagqala ezimhlophe-15% ngaphantsi ngengeniso ezinokuthelekiswa non-amagqala . Abanye abaphandi wasebenzisa iqhinga efana ngokunjalo. Umzekelo, Conley and Heerwig (2011) ezidityanisiweyo ulwazi malunga lowo randomly Kukhethwe uyilo kunye data nendlu eqokelelwe ukususela 2000 Census 2005 American Community Survey waza wafumanisa ukuba elide kangaka emva idrafti apho, waye ukusebenza elincinane ixesha elide emkhosini ezahlukeneyo kwiziphumo ezifana lwengqesho yezindlu (ongumnini kuthelekiswa nokurenta) kunye nozinzo yokuhlala (amathuba wasikwa kwiminyaka emihlanu edlulileyo).
Njengoko lo mzekelo ubonisa, ngamanye amaxesha imikhosi kwezentlalo, ezopolitiko, okanye zemvelo ukudala eksperimenti okanye kufutshane-eksperimenti ukuze kufumaneke ngabaphandi. Ngokufuthi imifuniselo yendalo zezona ndlela ukuqikelela ubudlelwane unobangela kunye nesiphumo kwiindawo apho kungekho ezisesikweni okanye okwenziwayo ukubaleka olungenamkhethe imifuniselo elawulwayo. Ke isicwangciso kubalulekile ukufumana uthelekiso fair data non-zovavanyo. Esi sicwangciso uphando ingashwankathelwa ngale nxaki:
\ [\ umbhalo {oluzenzekelayo (okanye ngokungathi oluzenzekelayo) isiganeko} + \ umbhalo {usoloko-on umlambo data} = \ umbhalo {ilinge yendalo} \ qquad (2.1) \]
Nangona kunjalo, uhlalutyo yemifuniselo zendalo ukusetyenziswa kumxholo wawakhoakulula. Ngokomzekelo, kwimeko idrafti Vietnam, asinguye wonk 'umntu ukuba uyilo-abafanelekileyo baphelela ukukhonza (bekukho iintlobo nokunyinyiselwa). Ke kaloku, ngelo xesha, abanye abantu abangakhange bayile-abafanelekileyo ngokuzithandela kwinkonzo. Kwaba ngathi xa ulingo lwezonyango ngayo ichiza elitsha, abanye abantu kwiqela kunyango abazange bathathe amayeza abo kunye nabanye abantu iqela lolawulo ngandlel wafumana iziyobisi. Le ngxaki, ebizwa noncompliance-ezinamacala amabini, kwakunye nezinye iingxaki ezininzi ichazwe ngokwenkcukacha enkulu kwezinye yokufundwa olukhuthazwayo ekupheleni kwesi sahluko.
Yesicwangciso wokuxhakamfula eyenzeka ngokwendalo umsebenzi ozenzekelayo olwandulela ubudala yesuntswana, kodwa ukuxhaphaka data enkulu kwenza esi sicwangciso lula ukuwasebenzisa. Wakuba uqonde ezinye unyango sele lafaka, imithombo yedatha ezinkulu lungabonelela data isiphumo ukuba ufuna ukuze uthelekise iziphumo abantu kwimiqathango unyango kunye nolawulo. Ngokomzekelo, kwisifundo kwakhe iziphumo uyilo kunye emkhosini, Angrist wasebenzisa iirekhodi ingeniso evela Administration yoKhuseleko lweNtlalo; ngaphandle kweli data isiphumo, ukufunda kwakhe kwakungayi kuba lula. Kulo mzekelo, uLawulo loKhuseleko loLuntu ke kusoloko-on ezinkulu umthombo wolwazi. Njengoko kukho imithombo yedatha ngakumbi ngokuzenzekelayo ziqokelelwe, siya kuba ngaphezu isiphumo data ukuba sokukala iziphumo zotshintsho wadalwa Umahluko ngaphandle.
Ukuzekelisa esi sicwangciso kweminyaka yesuntswana, makhe siqwalasele Mas and Moretti ngayo (2009) uphando ezintle kwi nefuthe oontanga kwimveliso. Nangona phezu komhlaba ukuze khangela ezahlukeneyo ngaphandle ko kufunda Angrist ngokuphathelele imiphumo Vietnam Draft, kubume bobabini balandela ipateni eq. 2.1.
Mas kunye Moretti walinganisa ukuba oontanga kuchaphazela imveliso lwabasebenzi. Kwelinye icala, ukuba ikholwane ukusebenza nzima ukuze kunokukhokelela abasebenzi ukwandisa imveliso yabo ngenxa ingcinezelo yoontanga. Okanye, kwelinye icala, ihlakani ukusebenza nzima ukuze kunokukhokelela abanye abasebenzi ukuba sekumnyam 'entla ngakumbi. Indlela cileyo ukufunda iziphumo peer kwimveliso owayeza kuba kwelinge alawulwayo apho abasebenzi ngokungenamkhethe kweenguqu kunye nabasebenzi amanqanaba imveliso kunye nemveliso leyo ke ilinganiswa wonke. Abaphandi ke, musa ukulawula ishedyuli kwabasebenzi kulo naliphi na ishishini lenene, njalo Mas kunye Moretti yaxhomekeka kwelinge zendalo lwenzeka evenkileni.
Kanye eq. 2.1, ukufunda neenxalenye ezimbini. Okokuqala, basebenzisa logs kwinkqubo esuphamakethi babesiya ukuba ngqo, ngamnye, yaye usoloko-on umlinganiselo yemveliso: inani lezinto scan ngomzuzwana. Kunye, okwesibini, ngenxa indlela kwamaxesha kwenziwa kule ivenkile, kufuneka kufuphi ukwakhiwa random noontanga. Ngamanye amazwi, nangona kwamaxesha kwiitila ayixhomekekanga leloto, oko eneni oluzenzekelayo. Ukuziqhelisa, intembelo esinayo amalinge zendalo rhoqo oluxhomekeke badala le "njengoko-ukuba" ibango oluzenzekelayo. Baxhamla kweli ongenabuyambo efunisela, Mas kunye Moretti wafumanisa ukuba ukusebenza kunye noontanga imveliso eziphezulu kwandisa imveliso. Ngaphezu koko, Mas kunye Moretti wasebenzisa ubungakanani, nobutyebi dataset kwabo ukuhamba ngaphaya yengqikelelo unobangela-kwaye-isiphumo ukuba baphicothe imibandela emibini ebalulekileyo kakhulu nangokufihlakeleyo: ukungafani le isiphumo (apho iintlobo abasebenzi na isiphumo ezinkulu), nendlela ngasemva isiphumo (kutheni ukuba oontanga eliphezulu imveliso kukhokelela imveliso eziphezulu). Siya kubuyela ezi ezimbini ezibalulekileyo miba-ukungafani ye iziphumo zonyango kunye neendlela-kwiSahluko 5 xa sixubusha eksperimenti iinkcukacha ezingaphezulu.
Generalizing kwizifundo phezu isiphumo Vietnam eYilwayo yengeniso kunye ukufunda ifuthe oontanga kwimveliso, Uluhlu 2.3 lushwankathela amanye amaphononongo zinamaqoqo ngqo mnye: usebenzisa usoloko-nomthombo data ukulinganisa ifuthe kwezinye . Njengoko Uluhlu 2.3 yenza ngokucacileyo, amalinge yendalo akuzo zonke iindawo ukuba nje uyazi ukuba khangela njani kubo.
| ingqwalasela substantive | Umthombo zovavanyo yendalo | Soloko-on umthombo weenkcukacha | isamani |
|---|---|---|---|
| Peer iziphumo kwimveliso | inkqubo emiselweyo | data yokuphuma | Mas and Moretti (2009) |
| Friendship ukusekwa | iinkanyamba | Phan and Airoldi (2015) | |
| Ukunaba neemvakalelo | imvula | Coviello et al. (2014) | |
| Umhlobo kumhlobo transfers zoqoqosho | inyikima | mobile data imali | Blumenstock, Fafchamps, and Eagle (2011) |
| ukuziphatha zityiwe | 2013 US angavala urhulumente | data imali zobuqu | Baker and Yannelis (2015) |
| nefuthe loqoqosho iinkqubo recommender | ezahlukeneyo | data yokhangelo e Amazon | Sharma, Hofman, and Watts (2015) |
| Isiphumo uxinezeleko nakubantwana olungekazalwa | 2006 amaSirayeli-Hezbollah imfazwe | iirekhodi Birth | Torche and Shwed (2015) |
| Ukufunda isimilo Wikipedia | Snowden nezityhilelo | logs Wikipedia | Penney (2016) |
Ukuziqhelisa, abaphandi basebenzise iindlela ezimbini ezahlukeneyo unokubafumana imifuniselo zendalo, zombini zingaba nempumelelo. Abanye abaphandi uqale usoloko-kwidata yemvelaphi kwaye khangela zeziganeko nandawoni ehlabathini; abanye beqalisa neziganeko nandawoni ehlabathini kwaye ukhangele imithombo yedatha ukuba ukufaka ifuthe lazo. Okokugqibela, qaphela ukuba amandla experimenti yendalo ayizwi ukusuka Ukuntsonkotha zohlalutyo manani, kodwa ukususela unonophelo kukubanceda uthelekiso fair wadalwa kwingozi ubenethamsanqa kwimbali.
