why we make bad decisionsWord文件下载.docx
- 文档编号:17305610
- 上传时间:2022-12-01
- 格式:DOCX
- 页数:10
- 大小:28.08KB
why we make bad decisionsWord文件下载.docx
《why we make bad decisionsWord文件下载.docx》由会员分享,可在线阅读,更多相关《why we make bad decisionsWord文件下载.docx(10页珍藏版)》请在冰豆网上搜索。
andthevalueofthatgaintous.
1:
18Inasense,whatBernoulliwassayingis,
ifwecanestimateandmultiplythesetwothings,
wewillalwaysknowpreciselyhowweshouldbehave.
26Now,thissimpleequation,evenforthoseofyou
whodon'
tlikeequations,issomethingthatyou'
requiteusedto.
Here'
sanexample:
ifIweretotellyou,let'
splay
alittlecointossgame,andI'
mgoingtoflipacoin,
andifitcomesupheads,I'
mgoingtopayyou10dollars,
butyouhavetopayfourdollarsfortheprivilegeofplayingwithme,
mostofyouwouldsay,sure,I'
lltakethatbet.Becauseyouknow
thattheoddsofyouwinningareonehalf,thegainifyoudois10dollars,
thatmultipliestofive,andthat'
smorethanI'
mchargingyoutoplay.So,theansweris,yes.
Thisiswhatstatisticianstechnicallycalladamnfinebet.
2:
03Now,theideaissimplewhenwe'
reapplyingittocointosses,
butinfact,it'
snotverysimpleineverydaylife.
Peoplearehorribleatestimatingbothofthesethings,
andthat'
swhatIwanttotalktoyouabouttoday.
16Therearetwokindsoferrorspeoplemakewhentryingtodecide
whattherightthingistodo,andthoseare
errorsinestimatingtheoddsthatthey'
regoingtosucceed,
anderrorsinestimatingthevalueoftheirownsuccess.
Now,letmetalkaboutthefirstonefirst.
Calculatingoddswouldseemtobesomethingrathereasy:
therearesixsidestoadie,twosidestoacoin,52cardsinadeck.
Youallknowwhatthelikelihoodisofpullingtheaceofspades
orofflippingaheads.
Butasitturnsout,thisisnotaveryeasyideatoapply
ineverydaylife.That'
swhyAmericansspendmore--
Ishouldsay,losemore--gamblingthanonallotherformsofentertainmentcombined.
Thereasonis,thisisn'
thowpeopledoodds.
3:
02Thewaypeoplefigureodds
requiresthatwefirsttalkabitaboutpigs.
Now,thequestionI'
mgoingtoputtoyouiswhetheryouthink
therearemoredogsorpigsonleashes
observedinanyparticulardayinOxford.
Andofcourse,youallknowthattheanswerisdogs.
Andthewaythatyouknowthattheanswerisdogsis
youquicklyreviewedinmemorythetimes
you'
veseendogsandpigsonleashes.
Itwasveryeasytorememberseeingdogs,
notsoeasytorememberpigs.Andeachoneofyouassumed
thatifdogsonleashescamemorequicklytoyourmind,
thendogsonleashesaremoreprobable.
That'
snotabadruleofthumb,exceptwhenitis.
40So,forexample,here'
sawordpuzzle.
Aretheremorefour-letterEnglishwords
withRinthethirdplaceorRinthefirstplace?
Well,youcheckmemoryverybriefly,makeaquickscan,
andit'
sawfullyeasytosaytoyourself,Ring,Rang,Rung,
andveryhardtosaytoyourself,Pare,Park:
theycomemoreslowly.Butinfact,therearemanymorewordsintheEnglishlanguage
withRinthethirdthanthefirstplace.
ThereasonwordswithRinthethirdplacecomeslowlytoyourmind
isn'
tbecausethey'
reimprobable,unlikelyorinfrequent.
It'
sbecausethemindrecallswordsbytheirfirstletter.
Youkindofshoutoutthesound,S--andthewordcomes.
slikethedictionary;
it'
shardtolookthingsupbythethirdletter.
So,thisisanexampleofhowthisideathat
thequicknesswithwhichthingscometomind
cangiveyouasenseoftheirprobability--
4:
30howthisideacouldleadyouastray.It'
snotjustpuzzles,though.
Forexample,whenAmericansareaskedtoestimatetheodds
thattheywilldieinavarietyofinterestingways--
theseareestimatesofnumberofdeathsperyear
per200millionU.S.citizens.
Andthesearejustordinarypeoplelikeyourselveswhoareasked
toguesshowmanypeoplediefromtornado,fireworks,asthma,drowning,etc.Comparethesetotheactualnumbers.
54Now,youseeaveryinterestingpatternhere,whichisfirstofall,
twothingsarevastlyover-estimated,namelytornadoesandfireworks.
Twothingsarevastlyunderestimated:
dyingbydrowninganddyingbyasthma.Why?
Whenwasthelasttimethatyoupickedupanewspaper
andtheheadlinewas,"
BoydiesofAsthma?
"
snotinterestingbecauseit'
ssocommon.
sveryeasyforallofustobringtomindinstances
ofnewsstoriesornewsreelswherewe'
veseen
tornadoesdevastatingcities,orsomepoorschmuck
who'
sblownhishandsoffwithafireworkontheFourthofJuly.
Drowningsandasthmadeathsdon'
tgetmuchcoverage.
Theydon'
tcomequicklytomind,andasaresult,
wevastlyunderestimatethem.
5:
36Indeed,thisiskindofliketheSesameStreetgame
of"
Whichthingdoesn'
tbelong?
Andyou'
rerighttosay
stheswimmingpoolthatdoesn'
tbelong,becausetheswimmingpool
istheonlythingonthisslidethat'
sactuallyverydangerous.
Thewaythatmoreofyouarelikelytodiethanthecombination
ofallthreeoftheothersthatyouseeontheslide.
55Thelotteryisanexcellentexample,ofcourse--anexcellenttest-case
ofpeople'
sabilitytocomputeprobabilities.
Andeconomists--forgiveme,forthoseofyouwhoplaythelottery--
buteconomists,atleastamongthemselves,refertothelottery
asastupiditytax,becausetheoddsofgettinganypayoff
byinvestingyourmoneyinalotteryticket
areapproximatelyequivalenttoflushingthemoney
directlydownthetoilet--which,bytheway,
doesn'
trequirethatyouactuallygotothestoreandbuyanything.
6:
23Whyintheworldwouldanybodyeverplaythelottery?
Well,therearemanyanswers,butoneanswersurelyis,
weseealotofwinners.Right?
Whenthiscouplewinsthelottery,
orEdMcMahonshowsupatyourdoorwiththisgiantcheck--
howthehelldoyoucashthingsthatsize,Idon'
tknow.
WeseethisonTV;
wereadaboutitinthepaper.
Whenwasthelasttimethatyousawextensiveinterviews
witheverybodywholost?
Indeed,ifwerequiredthattelevisionstationsrun
a30-secondinterviewwitheachloser
everytimetheyinterviewawinner,the100millionlosers
inthelastlotterywouldrequirenine-and-a-halfyears
ofyourundividedattentionjusttowatchthemsay,
Me?
Ilost."
"
Now,ifyouwatchnine-and-a-halfyearsoftelevision--
nosleep,nopottybreaks--andyousawlossafterlossafterloss,andthenattheendthere'
s30secondsof,"
andIwon,"
thelikelihoodthatyouwouldplaythelotteryisverysmall.
7:
17Look,Icanprovethistoyou:
here'
salittlelottery.
There'
s10ticketsinthislottery.
Nineofthemhavebeensoldtotheseindividuals.
Itcostsyouadollartobuytheticketand,ifyouwin,
youget20bucks.Isthisagoodbet?
Well,Bernoullitellsusitis.
Theexpectedvalueofthislotteryistwodollars;
thisisalotteryinwhichyoushouldinvestyourmoney.
Andmostpeoplesay,"
OK,I'
llplay."
39Now,aslightlydifferentversionofthislottery:
imaginethatthenineticketsareallowned
byonefatguynamedLeroy.
Leroyhasninetickets;
there'
soneleft.
Doyouwantit?
Mostpeoplewon'
tplaythislottery.Now,youcanseetheoddsofwinninghaven'
tchanged,
butit'
snowfantasticallyeasytoimaginewho'
sgoingtowin.
seasytoseeLeroygettingthecheck,right?
Youcan'
tsaytoyourself,"
I'
maslikelytowinasanybody,"
becauseyou'
renotaslikelytowinasLeroy.
Thefactthatallthoseticketsareownedbyoneguy
changesyourdecisiontoplay,
eventhoughitdoesnothingwhatsoevertotheodds.
8:
13Now,estimatingodds,asdifficultasitmayseem,isapieceofcake
comparedtotryingtoestimatevalue:
tryingtosaywhatsomethingisworth,howmuchwe'
llenjoyit,
howmuchpleasureitwillgiveus.
Iwanttotalknowabouterrorsinvalue.
HowmuchisthisBigMacworth?
Isitworth25dollars?
Mostofyouhavetheintuitionthatit'
snot--
youwouldn'
tpaythatforit.
37Butinfact,todecidewhetheraBigMacisworth25dollarsrequires
thatyouaskone,andonlyonequestion,whichis:
WhatelsecanIdowith25dollars?
Ifyou'
veevergottenononeofthoselong-haulflightstoAustralia
andrealizedthatthey'
renotgoingtoserveyouanyfood,
butsomebodyintherowinfrontofyouhasjustopened
theMcDonald'
sbag,andthesmellofgoldenarches
iswaftingovertheseat,youthink,
Ican'
tdoanythingelsewiththis25dollarsfor16hours.
tevensetitonfire--theytookmycigarettelighter!
Suddenly,25dollarsforaBigMacmightbeagooddeal.
9:
10Ontheotherhand,ifyou'
revisitinganunderdevelopedcountry,
and25dollarsbuysyouagourmetmeal,it'
sexorbitantforaBigMac.
Whywereyouallsurethattheanswertothequestionwasno,
beforeI'
deventoldyouanythingaboutthecontext?
BecausemostofyoucomparedthepriceofthisBigMac
tothepriceyou'
reusedtopaying.Ratherthanasking,
WhatelsecanIdowithmymoney,"
comparingthisinvestment
tootherpossibleinvestments,youcomparedtothepast.
Andthisis
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- why we make bad decisions