Wolfgang Lutz|Endale Birhanu Kebede
Education and Health: Redrawing the Preston Curve
population development reviewvolume 44 issue 2 p 343361 data perspectivesopen access education health redrawing preston curve wolfgang lutz wolfgang lutzsearch papers authorendale kebede endale kebedesearch papers author wolfgang lutz wolfgang lutzsearch papers authorendale kebede endale kebedesearch papers author first published 14 april 2018 httpsdoiorg101111padr12141citations 53aboutsectionspdf toolsrequest permissionexport citationadd favoritestrack citation shareshare give accessshare full text accessshare fulltext accessplease review terms conditions use check box share fulltext version articlei read accept wiley online library terms conditions useshareable linkuse link share fulltext version article friends colleagues learn morecopy url share linkshare onfacebooktwitterlinkedinredditwechat progress human health life expectancy closely associated socioeconomic development better nutrition greater affordability health care associated higher income widely considered primary determinants historical contemporary mortality declines mckeowns 1976 influential book modern rise population attributed secular mortality decline largely improving standards living reviewing mortality improvements britain second half nineteenth century beginning twentieth argued medical discoveries little consequence significant gains survival period analysis served reference point prestons 1975 article focus present study preston showed global pattern twentieth century indicates upward shift curve links gdp per person horizontal axis life expectancy vertical figure 11 preston interpreted shift effect medical progress health care effect income many studies issue followed prestons lead assumption income important driver mortality decline unquestioned starting point figure 1open figure viewerpowerpoint scatterdiagram relations life expectancy birth e0 national income per head nations 1900s 1930s 1960s preston 19751 different picture drawn caldwell 1986 article routes low mortality poor countries based major rockefeller foundation study kerala india sri lanka costa rica caldwell discussed factors led breakthrough mortality declines populations opposed others identified female autonomy saw largely function female education single important factor together efficient local health services also stated conclusion low mortality come unplanned spinoff economic growth step todays dominant economic political ideologies development field caldwell 1986 p 209 still seems case three decades later despite fact recent research points overriding importance education associated cognitive changes affecting risk perception planning horizon access information promoting healthrelated behaviors use health care facilities baker et al 2011 lutz skirbekk 2014 question whether income education important determinant global health mortality decline relevant setting policy priorities developing industrialized countries answer immediate concern choosing programs directly promote economic growth focus enhancing school enrollment quality schooling ideal world one would choose addition good local health services reality even rich countries budgetary constraints require policymakers set priorities helping set priorities necessary assess relative importance factors question relative importance focus follows address issue macro level plotting modification preston curve gdp per person replaced mean years schooling among adult population done life expectancy birth child mortality cases educational attainment explains pattern better gdp per person redrawing curve complemented multivariate analysis quantitatively assess relative difference two effects preston curve perception 1975 samuel preston published influential paper changing relation mortality level economic development plots global relationship gdp per capita life expectancy different points time finds time curve depicts relationship moved upward implying similar level income associated higher life expectancy later points time preston 1975 attributes extra gain medical progress view relationship known preston curve since become widely cited although preston cautious interpreting relationship association necessarily causal one subsequent interpretations relation often doubt based direct causation eg pritchett summers 1996 elaborate followup study preston 1980 introduced literacy calorie supply addition gdp per person regression models explain differences levels life expectancy 36 countries 1940 120 countries 1970 estimated coefficients showed similar patterns times literacy highly significant prestons words coefficients indicate 10 percentage point increase literacy associated points gain life expectancy approximately 2 years 10 percent gain national income increases life expectancy approximately onehalf year preston 1980 p 306 interesting findings however largely overlooked subsequent research development mortality apparent positive association income health given rise widespread view among development economists increased wealth leads causally increased health extreme pritchett summers 1996 argue focusing economic growth developing countries lead directly reductions infant mortality rates gains life expectancy many economists hold less definitive position acknowledge drivers addition income possibility apparent empirical association income health could largely spurious causal nature considered body economic literature 2007 issue international journal epidemiology devoted reprint prestons 1975 article several comments distinguished scholars field iea 2007 contribution relevant analysis bloom canning 2007 revisit preston curve state paper remains cornerstone global public health policy academic discussion public health prestons paper illuminates two central stylized facts first strong positive relationship national income levels life expectancy poorer countries though relationship nonlinear life expectancy levels richer countries less sensitive variations average income second relationship changing life expectancy increasing time income levels although basic facts set preston generally accepted still great deal dispute mechanisms lie behind relationships policy implications draw p 498 bloom canning also point another body literature public health example cutler deaton llerasmuney 2006 conclude scientific technical advances seen ultimate determinant health argument focusing income growth primary method reducing burden ill health lies apparently weak temporal association periods economic growth periods improvement population health suggesting relationship causal long variable lags rising incomes imply greater resources society resources need necessarily spent ways improve health bloom canning question basic assumption income growth health closely linked add cautionary sentence starting point study although strong case direct effect income health due nutrition health interventions becoming affordable may income also acting proxy wider measure socioeconomic status development causal effect due mechanisms example education p 498 recent assessment preston curve mackenbach looman 2013 find european countries increases life expectancy 1960 accompanied much smaller upward shift curve previously attribute changing pattern causes death away infectious diseases conclude declines mortality cardiovascular disease mainly attributable increases national income conclusion seems reached simply eliminating medical progress dominating reason assuming possible determinant mortality income thus cause decline possibility another driver jointly determines income health causes correlation considered article address hypothesis apparent statistical association income healthas described preston curvecould fact largely spurious association resulting fact improving educational attainment key determinant better health rising incomes discuss issue causality causality question causal nature effects education income health attracted much attention controversy question needs addressed order rule possibility associations interpreted could also spurious question important policy implications instance empirical association income health directly causal rather due third factor education increase incomeeg policies directly aiming economic growthwould result expected health improvements unless educational attainment also improved simultaneously true mutatis mutandis association educational attainment health causality social sciences viewed differently natural sciences human behavior culturally embedded found direct causation behavior given setting cannot assumed universal predictive power societies times inspired comprehensive review causality demography n bhrolchin dyson 2007 lutz skirbekk 2014 introduced notion functional causality context intervention sciences lutz striessnig 2015 pearl 2000 intervention sciences social economic sciences try understand important forces change society function order predict future evolution social system conditional predictions future trends based assumption intervention alternative interventions likely consequences establish functional causality three criteria met must strong empirically observed associations two factors studied ii must plausible narrative mechanisms one force influences iii obvious competing explanations observed association ruled examples competing explanations selfselection reverse causality joint determination third force lutz kc 2011 lutz skirbekk 2014 lutz skirbekk 2014 give comprehensive overview dozens relevant studies topic conclude justified assume functional causality globallevel relationship educational attainment healthmortality twentieth twentyfirst centuries several global assessments relationship health mortality baker et al 2011 kc lentzner 2010 pamuk fuchs lutz 2011 show continents different levels socioeconomic development lesseducated segments population significantly higher mortality morbidity better educated virtually countries children bettereducated mothers experience lower mortality since bettereducated people also tend live richer households question arises important child survival developing countries mothers education household incomewealth question focus studies using largest available individuallevel data set pooling samples demographic health surveys dhs 43 developing countries fuchs pamuk lutz 2010 pamuk fuchs lutz 2011 using multilevel regression models analysis relative effects mothers education economic resources infant mortality family community country levels shows effect education clearly dominates incomewealth levels empirical evidence equally compelling effect education adult mortality virtually countries data exist bettereducated people higher life expectancies caselli et al 2014 differences vary extent among countries generally greater men women among industrialized countries differences tend lowest southern european countries highest eastern europe russia difference highest lowest education groups among adult men 12 years caselli et al 2014 also shown overall decline life expectancy russian men experienced 1990s driven strong decline among lower education groups whereas highest groups continued enjoy moderate increases shkolnikov et al 2006 virtually industrialized countries data available education differentials adult mortality increased time despite improving health care coverage countries caselli et al 2014 one explanation pattern lies increasing importance lifestylerelated factors education seems important health care system plausible narrative causation founded brain research demonstrated literacy education general enhance synaptic density relevant parts brains thus makes us physiologically different rest lives kandel 2007 also shown controlled experiment among illiterate indian young adult men subsample taught read write lasting structural changes brains six months learning associated executive functioning cognitive abilities baker salinas eslinger 2012 blair et al 2005 brinch galloway 2012 skeide et al 2017 neurocognitive neuroimaging studies shown strong associations adaptive changes brain learning experiences classroom lewis et al 2009 welberg 2009 changes shown associated ability abstract thinking time preference capacity plan future cutler llerasmuney 2010 kenkel 1991 van der pol 2011 heckman humphries veramendi 2017 cognitive changes resulting changes behavior relevance health outcomes context also stressed large number studies focus natural experiments educationhealth link looking changes compulsory schooling year seem promising route refer plausible causal pathway young people forced stay school ten rather nine years unlikely result significant change overall brain functioning would expected direct health effects relevant changes shown major cognitive transitions illiterate literate compulsory postsecondary education cutler llerasmuney 2010 peters et al 2006 skeide et al 2017 another concern context assessing functional causality possibility reverse causality also implicit notion simultaneity pose difficult challenge reason assume simultaneous influences going directions models granger causality used sort temporal sequence possible effects basis causal inference based principle cause needs precede effect case education models unnecessary temporal sequence identified priori schooling tends happen early life course human capital education stock adult ages expected consequences healthrelated behavior time lag schooling happens education flow resulting stock human capital influences health many decades study educationhealth differentials people age 70 even half century hence proper distinction made education flow educational attainment way period conditions time including income medical inventions etc influence schooling occurred decades respect possibility empirical association caused third factor different pathways causation need distinguished figure 2 shows possible interactions education health income form triangle education health base income top cognitive skills associated adult educational attainment persons health status closely interwoven embodied individuals certain minimum level physical health necessary child develop mentally able attend school particularly developing countries school absenteeism due poor health children family members must care whose lost economic output must compensate serious handicap improving levels education consequently building key cognitive skills raising learning outcomes similarly children often bring home school knowledge attitudes access information relevant health even survival family members figure 2open figure viewerpowerpoint triangular interactions education flows stocks health income better health longer lives closely linked education cognitive capacity also turn directly affect economic growth growing literature shows health direct source human welfare driver income growth bloom canning 2008 particular three mechanisms defined better health leading higher labor productivity better childhood health leading better school attendance cognitive development longer expected life span leading savings investment empirical studies also find good health positive sizable statistically significant effect aggregate output even controlling experience work force bloom canning sevilla 2003 whosponsored report commission macroeconomics health sachs 2001 also highlighted importance basic health poverty reduction showing burden diseases lowincome countries especially subsaharan africa barrier economic growth therefore addressed comprehensive development strategy finally effect improving educational attainment quality education long part economic growth theory past empirical efforts demonstrate effect basis aggregate time series hampered lack appropriate data educational attainment de la fuente domnech 2006 recent assessments based full educational attainment distributions age cohorts demonstrate consistently positive significant effect human capital economic growth crespo cuaresma lutz sanderson 2014 lutz crespo cuaresma sanderson 2008 shown respect quality education countries data exist hanushek woessmann 2008 updating global empirical analysis 19702010 explore association educational attainment income mortality across time space employ balanced panel 174 countries developed developing period 19702010 fiveyear intervals following logic prestons 1975 1980 papers first present graphical presentations bivariate relationship gdp per person life expectancy followed multivariate statistical analyses also study pattern respect child mortality dichotomous variable literacy one available preston use mean years schooling adult population aged 15 older case life expectancy women aged 2039 case child mortality data data obtained mainly two sources countrylevel indicators educational attainment years 19702015 extracted wittgenstein centre data explorer wic 2015 panel data income mortality obtained world development indicators world bank 2017 merging two datasets gave us panel data missing data countries earlier years following prestons original design income measured gdp per person 2010 constant usd multivariate analysis also performed sensitivity runs ppp purchasing power parity per person used instead constant 2010 usd descriptive analysis figure 3 presents visual analysis crosscountry associations income educational attainment life expectancy years 1970 1990 2010 similar way preston 1975 plotted life expectancy gdp per person 1930s 1960s panel plot life expectancy birth gdp per person 1970 1990 2010 closely resembles pattern original preston curve figure 1 curve clearly continues move upward time according preston due factors income assumed mostly related medical progress health care panel b figure shows isomorphic curve difference gdp per person replaced mean years schooling adult population mys15 resulting pattern however differs considerably rising educational attainment seems explain rising life expectancy much better gdp per person association looks much linear without leveling higher levels little upward shift would indicate unexplained gap needs explained medical progress figure 3open figure viewerpowerpoint relationship real gdp per person constant usd life expectancy birth panel mean years schooling mys adult population aged 15 life expectancy birth panel b 1970 1990 2010 note 174 countries lines show fitted splines figure 4 shows corresponding pair curves life expectancy replaced child mortality aged 04 order see whether previous pattern also holds mortality rate often easily influenced targeted health interventions overall life expectancy mean years schooling women aged 2039 used education indicator panel plot child mortality gdp per person shows essentially pattern life expectancy vs gdp per person panel figure 3 panel b figure reveals relationship looks much linear education gdp per person 19701990 shift curves changes mothers education evidently explaining declining child mortality much better gdp per person 19902010 however interesting deviation general pattern child mortality highmortalityloweducation countries declines rapidly would expected gains mothers education period evidently consequence massive international child health interventions countries past two decades shows least respect child mortality concerted public health efforts lower mortality social development alone would predict figure 4open figure viewerpowerpoint relationship real gdp per person constant usd child mortality u5mr panel mean years schooling mys women aged 2039 child mortalitypanel b 1970 1990 2010 note 174 countries lines show fitted splines multivariate analysis multivariate statistical analyses conducted explore relative effects education income explaining changing global mortality patterns conducting hausman test choose fixedeffect randomeffect specification countrylevel unobserved effects preferred fixedeffect model fitted specified follows 1 2where mortality indicator life expectancy birth child mortality country time represent unobservable individual country heterogeneities education indicator mean years schooling age 15 country time gdp per person constant 2010 usd country time controls year fixedeffect specified binary variable year observation number different models estimated addition main models shown tables 1 2 sensitivity analysis performed described sake comparison variables standardized zscores calculated fit models coefficients thus interpreted within given country gain health standard deviation standard deviation change independent variable first estimated country fixedeffect panel model including explanatory variable separately unadjusted effect predictor estimated shown column 1 second estimated model education income indicators shown column 2 finally column 3 gives full model income education country period fixedeffects table 1 panel data regressions period 19702015 population weighted country time fixedeffects indicated standardized coefficients life expectancy birth standardized dependent variable 1 2 3 variable unadjusted mutually adj main model gdp per person log 914 307 106 234 134 091 education 994 855 395 107 104 115 observations 1276 1276 rsquared 841 884 number countries 149 149 country fixedeffects yes yes yes year fixedeffects yes p001 p005 p01 notes gdp per person constant 2010 usd education mean years schooling population aged 15 robust standard errors parentheses table 2 panel data regressions period 19702015 population weighted country time fixedeffects indicated standardized coefficients underfive child mortality u5mr standardized dependent variable 1 2 3 variable unadjusted mutually adj main model gdp per person log 860 004 0772 029 118 0127 education 923 1214 1016 034 144 130 observations 1257 1257 rsquared 824 0831 number countries 147 147 country fixedeffects yes yes yes year fixedeffects yes p001 p005 p01 note gdp per person constant 2010 usd education mean years schooling women aged 2039 robust standard errors parentheses results life expectancy given table 1 show high significant unadjusted parameters income educa