fryer apollo presentation

31
The Impact of Apollo 20 on Student Achievement: Evidence from Year One by Roland G. Fryer, Jr. Robert M. Beren Professor of Economics Harvard University EdLabs NBER

Upload: enm077486

Post on 21-Feb-2015

5.880 views

Category:

Documents


5 download

TRANSCRIPT

Page 1: Fryer Apollo Presentation

   

The Impact of Apollo 20 on Student Achievement:

Evidence from Year One by

Roland G. Fryer, Jr. Robert M. Beren Professor of Economics

Harvard University EdLabs NBER

Page 2: Fryer Apollo Presentation

CONFIDENTIAL

Outline    Apollo  20  

 

Road-­‐map  for  the  talk:    A.  The  Achievement  Gap  in  America  B.  The  Five  Tenets:  Mo=va=on  and  Implementa=on  

1.  More  Time  in  School  2.  Small-­‐Group  Tutoring  and  Differen=a=on  3.  Human  Capital  Management  4.  Data-­‐Driven  Instruc=on  5.  Culture  and  High  Expecta=on  

C.  Explana=on  of  Empirical  Methodology  D.  Year  One  Results  E.  Verifica=on  Checks  F.  Context  and  Wrap-­‐up  

   

Page 3: Fryer Apollo Presentation

CONFIDENTIAL 3

Accoun&ng  for  educa&onal  achievement  dras&cally  reduces  racial  and  socioeconomic  inequality  across  a  wide  range  of  important  life  outcomes.  

28.0%

0.6% 0.0%

10.0%

20.0%

30.0%

Not Accounting for Educational Achievement

Accounting for Educational Achievement

The Black-White Wage Gap

182%

38%

0%

100%

200%

300%

Not Accounting for Educational Achievement

Accounting for Educational Achievement

The Black-White Incarceration Rate Gap

190%

90%

0%

100%

200%

300%

Not Accounting for Educational Achievement

Accounting for Educational Achievement

The Black-White Unemployment Gap

0.196

0.059

0

0.1

0.2

0.3

Not Accounting for Educational Achievement

Accounting for Educational Achievement

The Black-White Health Gap (in Standard Deviations)

Overview    Educa5onal  Achievement  Drives  Life  Outcomes  

Page 4: Fryer Apollo Presentation

CONFIDENTIAL

Among  ci&es  that  par&cipate  in  NAEP,  the  magnitude  of  racial  differences  in  educa&onal  achievement  is  startling.    

Overview    The  Achievement  Gap  

0  10  20  30  40  50  60  70  80  

Math  

White  

Black  

Hispanic  

0  10  20  30  40  50  60  70  80  

Reading  

White  

Black  

Hispanic  

Page 5: Fryer Apollo Presentation

CONFIDENTIAL

What’s  more,  “conven&onal  wisdom”  solu&ons  have  failed  to  solve  the  problem.    

22.3  :1  

20.4  :1  

18.7  :1  

17.9  :1  17.2  :1   17.3  :1  

16.0  :1   15.6  :1  

14:1  

16:1  

18:1  

20:1  

22:1  

24:1  

1970   1975   1980   1985   1990   1995   2000   2005  

Student  to  Teacher  Ra5o  

$5,243  $6,049   $6,268  

$7,347  $8,790   $8,949  

$10,508   $11,438  

$0  

$5,000  

$10,000  

1970   1975   1980   1985   1990   1995   2000   2005  

Total  Expenditure  Per  Pupil  (2008-­‐09  $))   $12,116  

23.5%   27.5%  49.6%   53.1%   56.8%   61.8%  

0%  

20%  

40%  

60%  

80%  

100%  

1961   1971   1981   1991   2001   2006  

Percentage  of  Teachers  with  a  Master's  Degree  or  Higher  

76.9%   73.6%   71.4%   72.4%   73.4%   69.3%   69.8%  75.4%   74.7%  

0%  

25%  

50%  

75%  

100%  

1970   1975   1980   1985   1990   1995   2000   2005  

HS  Graduates  as  a  ra5o  of  17  year-­‐old  popula5on  

175  

200  

225  

250  

275  

300  

325  

1971   1975   1980   1984   1988   1990   1994   1996   1999   2004   2008  

Reading  and  Math  Achievement  of  9,  13,  and  17  year-­‐olds,  1971-­‐2008  

9  year-­‐olds  

13  year-­‐olds  

Overview    Conven5onal  Wisdom  

Page 6: Fryer Apollo Presentation

CONFIDENTIAL

Given  the  current  rate  of  “No  Excuses”  charter  school  growth,  charters  will  take  over  half  a  century  to  educate  every  child  in  America  and  close  the  achievement  gap.      That’s  too  long.    We  are  faced  with  two  op=ons:      

1.  Create  a  market  in  which  only  gap  closing  charters  can  survive  (great  idea,  tough  poli=cs).  

2.  Boil  down  charter  school  successes  into  translatable,  scalable  prac=ces  for  public  schools.    

   

Scaling  Up  Charter  Success  Apollo  20  

 

Page 7: Fryer Apollo Presentation

CONFIDENTIAL

Scaling  Up  Charter  Success  Apollo  20  

 

One  of  the  original  missions  of  charter  schools  was  to  experiment  and  incubate  best  prac=ces  that  could  then  be  transferred  to  public  schools.      Dobbie  and  Fryer  (2011a)  examine  results  from  106  charter  schools  in  New  York  City  in  order  to  iden=fy  the  prac=ces  most  correlated  with  student  achievement.    They  find  that  accoun=ng  for  five  factors  explains  roughly  40%  of  the  variance  in  charter  school  performance.  

Page 8: Fryer Apollo Presentation

CONFIDENTIAL 8  

The  key  strategies  of  Apollo  schools.  

Scaling  Up  Charter  Success  Apollo  20  Strategies  

More Time in School •  Extended day, week, and school years are all integral components of successful school

models. In the case of Harlem Children’s Zone’s Promise Academy, students have nearly doubled the amount of time on task compared to students in NYC public schools.

Small Group Tutoring and Differentiation •  In top performing schools, classroom instruction is supplemented by individualized tutoring,

both after school and during the regular school day.

Human Capital Management •  Successful charters reward teachers for performance and hold them accountable if they are

not adding value.

Data-Driven Instruction •  In the top charter schools, students are assessed frequently, and then, in small groups, re-

taught the skills they have not yet mastered.

Culture and Expectations •  In successful schools, students buy into the school’s mission and into the importance of

their education in improving their lives.

Page 9: Fryer Apollo Presentation

CONFIDENTIAL

Implementa5on  Human  Capital  

 In  addi=on  to  finding  nine  new  principals,  teacher  turnover  spiked  to  53%  in  Apollo  schools  over  the  summer  of  2010.    Value-­‐added  data  shows  that  teachers  who  returned  as  Apollo  teachers  had  a  much  stronger  history  of  increasing  student  achievement  in  every  subject,  rela=ve  to  those  who  lea.  

-­‐0.7  

-­‐0.6  

-­‐0.5  

-­‐0.4  

-­‐0.3  

-­‐0.2  

-­‐0.1  

0  

0.1  

0.2  

Language   Math   Reading   Science   Social  Studies  

Teacher  Value  Added  

Lea  

Stayed  

0%  

10%  

20%  

30%  

40%  

50%  

60%  

2005-­‐06   2006-­‐07   2007-­‐08   2008-­‐09   2009-­‐10  

Teacher  Departure  Rates  

Apollo  Schools  

Comparison  Schools  

Page 10: Fryer Apollo Presentation

CONFIDENTIAL

Implementa5on  Increased  Time  in  School  

 The  school  day  was  extended  in  Apollo  schools  during  the  2010-­‐11  school  year:  7:45am  –  4:15pm  Monday  through  Thursday,  and  7:45am  –  3:15pm  on  Fridays.    This  was  an  average  of  an  hour  longer  per  school  day.  The  school  year  was  extended  by  five  school  days.    Apollo  students  reported  for  school  on  August  16,  2010,  while  the  rest  of  the  district  began  on  August  23,  2010.  

BoXom  line:  The  difference  between  instruc=onal  =me  in  2009-­‐10  and  2010-­‐11  amounts  to  approximately  30  school  days  –  that’s  6  addi5onal  weeks  of  school  for  students.    

0  

200  

400  

600  

800  

1000  

1200  

1400  

1600  

1800  

Pre-­‐Interven=on   Typical  NYC  Charter   Post-­‐Interven=on   No  Excuses  NYC  Charter  

Instruc5onal  Hours  per  Year  

Page 11: Fryer Apollo Presentation

CONFIDENTIAL

Implementa5on  High  Dosage  Differen5a5on:  Tutoring  and  Double-­‐Dosing  

 

Tutors  were  recruited  both  na=onally  and  locally  during  summer  2010.  •  1158  total  applicants  (through  August  9,  2010)  •  516  applicants  par=cipated  in  screening  •  319  offered  a  posi=on  •  257  accepted  a  posi=on  in  one  of  the  nine  schools  •  173  tutors  qualified  for  end-­‐of-­‐year  student  performance  bonuses,  earning  an  

average  of  $3,346.  •  96  tutors  are  returning  for  the  2011-­‐12  school  year  •  1156  6th  graders  and  1585  9th  graders  received  2:1  tutoring  in  the  2010-­‐11  school  

year.    Middle  school  students  received  approximately  215  hours  of  tutoring/double-­‐dosing  High  school  students  received  approximately  189  hours  of  tutoring/double-­‐dosing  

Page 12: Fryer Apollo Presentation

CONFIDENTIAL

Implementa5on  Data-­‐Driven  Instruc5on  

 

Students  were  regularly  assessed  in  order  to  provide  teachers  with  accurate  data  on  student  mastery.    In  addi=on  to  the  HISD  3-­‐week  interim  assessments,  the  Apollo  schools  administered  comprehensive  benchmark  assessments  according  to  the  schedule:    • Middle  school  reading  –  December,  February/March  • Middle  school  math  –  December,  February/March  • Middle  school  science  –  December,  March  • Middle  school  social  studies  –  December,  March  • High  school  ELA  –  December,  January  • High  school  math  –  December,  March  • High  school  science  –  December,  March  • High  school  social  studies  –  December,  March    Aaer  each  assessment,  teachers  received  student-­‐level  data  and  used  this  to  have  one-­‐on-­‐one  goal-­‐sehng  conversa=ons  with  students.  

Page 13: Fryer Apollo Presentation

CONFIDENTIAL

Implementa5on  Culture  and  Expecta5ons  

 

There  was  a  consistent  emphasis  on  college  matricula=on  at  the  Apollo  schools,  and  students  were  supported  in  their  efforts  to  apply  to  college.  

Apollo  High  Schools  College  Applica5on  and  Acceptance  Rates  

2-­‐Year   4-­‐Year  

Applied   Accepted   Applied   Accepted  

Jones  HS   95%   95%   60%   44%  

Kashmere  HS   90%   90%   89%   42%  

Lee  HS   97%   97%   84%   47%  

Sharpstown  HS   94%   94%   81%   55%  

“It  feels  like  we’re  actually  going  to  school  now.”  –  Lee  HS  student  

“We  have  supports  this  year  that  we  didn’t  have  in  the  past.”  –  Sharpstown  HS  student  

“School  is  harder…but  it’s  good  because  we’ll  be  ready.”  –  Key  MS  student

Page 14: Fryer Apollo Presentation

CONFIDENTIAL

Implementa5on  Culture  and  Expecta5ons  

 At  the  end  of  the  2009-­‐10  school  year,  TNTP  interviewed  teachers  in  schools  that  would  become  Apollo  schools  for  2010-­‐11.    Teachers  who  returned  as  Apollo  teachers  scored  higher  on  every  type  of  ques=on,  including  their  commitment  to  the  “No  Excuses”  philosophy  and  beliefs  that  all  students  are  capable  of  high  achievement.  

0  

0.5  

1  

1.5  

2  

2.5  

3  

3.5  

No  Excuses   Alignment  with  Mission  

Student  Achievement  

Commitment  to  Students  

Student  Mo=va=on  

Interview  Response  Scores  

Lea  

Stayed  

Page 15: Fryer Apollo Presentation

CONFIDENTIAL

Given  that  we  don’t  have  a  randomized  experiment  in  year  one,  we  use  several  empirical  methods  to  assess  the  impact  of  Apollo  20.      

Research  Design  Empirical  Strategies  

•  Ordinary  Least  Squares  Regression  

•  Advantages:    Simple  and  easy  to  interpret  •  Disadvantages:  Assumes  linear  func=onal  form  to  allow  comparisons  between  students  

of  different  sta=s=cal  profiles,    cannot  control  for  unobservable  differences  between  treatment  and  control  students  

•  Nearest  Neighbor  Matching  

•  Using  the  distance  func=on  defined  above,  we  locate  each  students’  four  closest  sta=s=cal  neighbors  and  compare  them  to  the  group  average.  

•  Advantages:    No  func=onal  form  assump=on,  focuses  aoen=on  on  students  from  similar  backgrounds  

•  Disadvantages:  Cannot  control  for  unobservable  differences  between  treatment  and  control  students.    

igisgsi XApolloscore εγβββ ++⋅+⋅+= 210,,

)()(),( jiji XXVXXjid −ʹ′−=

Page 16: Fryer Apollo Presentation

CONFIDENTIAL

Research  Design  Empirical  Strategies  

•  Difference  in  Differences    

•  Advantages:  By  focusing  on  year-­‐over-­‐year  changes  in  scores,  we  account  for  baseline  varia=on  that  we  do  not  otherwise  observe.  

•  While  these  methods  have  their  advantages,  all  three  will  be  biased  if  students  selec=vely  opt  in  or  out  of  Apollo  schools.  

sigisgsi XApolloscore ,210,, εγβββ ++⋅+⋅+=Δ

Page 17: Fryer Apollo Presentation

CONFIDENTIAL

Research  Design  Selec5on  Issues  

Incoming  Sixth  Graders  

Incoming  Ninth  Graders  

Page 18: Fryer Apollo Presentation

CONFIDENTIAL

•  To  account  for  the  decline  in  baseline  ability  in  Apollo  schools,  we  need  a  way  to  iden=fy  which  students  would  have  enrolled  in  the  absence  of  such  significant  changes.    This  leads  us  to  our  final    empirical  strategy,  which  uses  a  student’s  home  enrollment  zone  to  predict    which  students  are  likely  to  aoend  Apollo  schools.  

•  Two-­‐Stage-­‐Least-­‐Squares  Difference  in  Differences  

•  Advantages:  Solves  selec=on  issue.  •  Disadvantages:  Possibly  vulnerable  to  cri=ques  based  on  the  exclusion  

restric=on.

igiigsi XzonedApollo εγβββ ++⋅+⋅+= 210,,

Research  Design  Empirical  Strategies  

Page 19: Fryer Apollo Presentation

CONFIDENTIAL

Results  Main  Results  

0  

0.1  

0.2  

0.3  

0.4  

0.5  

0.6  

0.7  

0.8  

6   7  &  8   9   10  &  11  

TAKS  Math  Results  

OLS  

NNM  

DID  

2SLS  

In  Math,  we  see  posi=ve  and  sta=s=cally  significant  results  in  both  middle  and  high  school.    The  gains  in  grades  that  received  high-­‐dosage  tutoring  were  drama=c.    

Page 20: Fryer Apollo Presentation

CONFIDENTIAL

In  Reading/ELA,  the  results  are  mixed.    While  high  schools  performed  extremely  well,  there  is  liole  evidence  of  success  in  middle  school  –  indeed  some  es=mates  are  nega=ve.    

-­‐0.1  

-­‐0.05  

0  

0.05  

0.1  

0.15  

0.2  

0.25  

6   7  &  8   9   10  &  11  

TAKS  Reading  

OLS  

NNM  

DID  

2SLS  

Results  Main  Results  

Page 21: Fryer Apollo Presentation

CONFIDENTIAL

Verifica5on  Alternate  Test  

The  results  presented  so  far  are  extremely  promising.    However,  some  have  argued  that  the  gains  on  state  exams  can  be  driven  by  test-­‐specific  preparatory  ac=vi=es  at  the  expense  of  general  student  learning  (Jacob  2005,  Heilig  and  Darling-­‐Hammond  2008).    To  provide  some  evidence  on  this  maoer,  we  also  looked  at  Stanford  10  scores.    This  test  is  na=onally  normed  and  not  =ed  to  any  accountability  measure,  so  the  incen=ves  to  teach  to  the  test  or  otherwise  manipulate  results  are  minimal    

Page 22: Fryer Apollo Presentation

CONFIDENTIAL

Stanford   10   tests   show   a   similar   paoern   to   TAKS,   sugges=ng   that   our  results  are  not  driven  by  teaching  to  the  test.    

-­‐0.05  

0  

0.05  

0.1  

0.15  

0.2  

0.25  

0.3  

0.35  

6   7  &  8   9   10  &  11  

Stanford  Math  

OLS  

NNM  

DID  

2SLS  

-­‐0.2  

-­‐0.15  

-­‐0.1  

-­‐0.05  

0  

0.05  

0.1  

0.15  

0.2  

6   7  &  8   9   10  &  11  

Stanford  Reading  

OLS  

NNM  

DID  

2SLS  

Verifica5on  Alternate  Test  

Page 23: Fryer Apollo Presentation

CONFIDENTIAL

A  second  poten=al  threat  to  our  results  is  aori=on  from  our  sample.    Our  main  results  use  the  sample  of  students  who  enroll  in  an  Apollo  school  or  a  comparison  school  at  the  beginning  of  the  2010-­‐11  school  year  and  for  whom  we  have  test  score  data  in  the  spring  of  2011.    If  Apollo  students  are  more  likely  to  miss  the  Spring  2011  TAKS  examina=on,  this  could  bias  our  es=mates.        Given  the  major  and  sudden  changes  that  occurred  in  Apollo  schools,  it  is  plausible  that  parents  might  choose  to  move  their  children  to  a  private  school  or  a  charter  school  like  KIPP  or  YES.    In  these  instances,  we  would  not  observe  their  test  scores.    To  examine  this  issue,  we  es=mate  the  impact  of  Apollo  on  the  probability  of  entering  our  analysis  sample.  

Verifica5on  AXri5on  

Page 24: Fryer Apollo Presentation

CONFIDENTIAL

Verifica5on  AXri5on  

We  es=mate  that  Apollo  students  are  0.6%  more  likely  to  miss  an  exam  than  comparable  students  in  comparison  schools,  though  this  es=mate  is  not  sta=s=cally  significant.    Dropping  the  top  0.6%  of  Apollo  students  from  the  analysis  does  not  change  our  findings.    For  the  difference-­‐in-­‐difference  es=mates,  we  must  also  be  able  to  match  students  to  their  2009-­‐10  score  to  calculate  a  trend.    We  find  that  Apollo  students  are  roughly  4%  more  likely  to  be  missing  baseline  scores.    Since  we  are  able  to  replicate  our  DID  results  with  other  models  that  do  not  require  baseline  scores,  this  is  not  problema=c.        

Outcome   Marginal  Effect   Outcome   Marginal  Effect  

Missing  2011  Math   .006   Missing  2010  Math   .040***  

(.005)   (.017)  

Missing  2011  Rdg.   .006   Missing  2010  Rdg.   .038  

(.005)   (.017)  

Notes:  Standard  Errors  reported  in  parentheses.  

Page 25: Fryer Apollo Presentation

CONFIDENTIAL

Apollo  schools  were  also  subjected  to  unprecedented  levels  of  scru=ny  and  accountability  –  the  nine  principals,  in  par=cular,  earned  bonuses  for  mee=ng  performance  goals  and  could  be  terminated  if  they  fell  short.    One  might  worry  that  such  a  high-­‐stakes  environment  might  induce  school  officials  to  cheat  when  repor=ng  scores.    Accordingly,  we  examined  student  responses  on  the  2010-­‐11  TAKS  and  ranked  every  grade  in  every  school  according  to  four  measures  designed  to  detect  suspicious  paoerns  in  student  answers:    

1.  Unusual  blocks  of  consecu=ve  iden=cal  answers  given  by  mul=ple  test-­‐takers  2.  Unlikely  correla=on  in  answer  responses  within  grades  3.  Unusually  high  variance  in  these  correla=ons  4.  Unlikely  combina=ons  of  correct  answers  –  for  instance,  gehng  easy  

ques=ons  wrong  and  hard  ques=ons  correct  

Verifica5on  Chea5ng  Analysis  

Page 26: Fryer Apollo Presentation

CONFIDENTIAL

Verifica5on  Chea5ng  Analysis  

Aaer  adding  the  ranks  of  all  schools  and  grades  on  each  of  these  four  measures,  we  find  that  the  average  Apollo  school  is  in  the  43.9  percen=le  in  math  and  43.1  percen=le  in  reading.  

Page 27: Fryer Apollo Presentation

CONFIDENTIAL

Results  Subcomponents  

0  

0.1  

0.2  

0.3  

0.4  

0.5  

0.6  

6   9  

Tutoring  Effec5veness  

Above-­‐Grade  Comparison  

Reading  Comparison  

-­‐0.1  

-­‐0.05  

0  

0.05  

0.1  

0.15  

0.2  

0.25  

0.3  

7   8   10   11  

Double-­‐Dosing  Effec5veness  

Math  

Reading  

Unsurprisingly,  our  triple-­‐difference  analysis  shows  that  tutoring  was  highly  effec=ve  in  increasing  achievement.    The  double  dosing  results,  however,  are  all  sta=s=cally  zero  except  for  a  large  posi=ve  effect  in  eighth  grade  math.  

Page 28: Fryer Apollo Presentation

CONFIDENTIAL

Results  Context  

The  Apollo  results  are  strikingly  similar  to  the  effects  of  aoending  the  Harlem  Children’s  Zone  Promise  Academy  Middle  School,  KIPP  Lynn  Middle  School,  and  a  group  of  “No  Excuses”  Boston-­‐area  charters.  

Apollo  20    Harlem  

Children’s  Zone  

KIPP  Lynn   Boston  Charter  Schools  

Oversubscribed   All  Urban  

6th  Grd.  Math   .484   .249  

MS  Math    .234   .229   .346   .359   .148  

MS  Reading   -­‐.014   .047   .120   .198   .098  

9th  Grd.  Math   .739  

HS  Math   .368   .265   .122  

HS  Reading   .189   .364   .169  

Sources:  Dobbie  and  Fryer  (2010),  Dobbie  and  Fryer  (2011b),  Abdulkadiroglu  et  al  (2011),  Angrist  et  al.  (2010)  

Page 29: Fryer Apollo Presentation

CONFIDENTIAL

Results  Return  on  Investment  

Implemen=ng  Apollo  cost  roughly  $2,042  per  student.  A  back-­‐of-­‐the-­‐envelope  calcula=on  shows  that  that  internal  rate  of  return  from  this  investment  is  20.16%.    Compared  to  other  educa=onal  interven=ons,  this  return  is  large.  

Ini5a5ve   IRR  

Apollo  20   20.16  %  

“No  Excuses”  Charter  School   18.50  %  

Early  Childhood  Educa=on   7.99  %  

Reduced  Class  Size   6.20  %  

Sources:    Curto  and  Fryer  (2011),  Heckman  (2010),  Krueger  (2003)  

Page 30: Fryer Apollo Presentation

CONFIDENTIAL

       

 

Lessons  Learned    

The  main  takeaway  from  Apollo  Program  in  2010-­‐11  is  that  a  fully  loaded  Apollo  program  in  which  all  five  tenets  are  implemented  with  fidelity  produces  large,  significant  gains  in  student  performance.    We  must  think  hard  about  how  to  scale-­‐up  tutoring  in  a  manner  that  maximized  student  performance  while  controlling  the  costs  of  the  program.    

Page 31: Fryer Apollo Presentation

CONFIDENTIAL

References  

Abdulkadiroglu,  A=la,  Joshua  Angrist,  Susan  Dynarski,  Thomas  J.  Kane,  and  Parag  Pathak  (2011),  “Accountability  in  Public  Schools:  Evidence  from  Boston’s  Charters  and  Pilots”,  forthcoming  in  Quarterly  Journal  of  Economics.    Angrist,  Joshua  D.,  Susan  M.  Dynarski,  Thomas  J.  Kane,  Parag  A.  Pathak,  and  Christopher  R.  Walters.  2010.  "Inputs  and  Impacts  in  Charter  Schools:  KIPP  Lynn."  American  Economic  Review  Papers  and  Proceedings,  100(2):  239–43.    Dobbie,  Will  and  Fryer,  Roland  G.  (2011a),  “Are  High  Quality  Schools  Enough  to  Increase  Achievement  Among  the  Poor?  Evidence  From  the  Harlem  Children’s  Zone”,  Forthcoming  in  American  Economic  Journal:  Applied  Economics.    Dobbie,  Will  and  Fryer,  Roland  G.  (2011a),  “Are  High  Quality  Schools  Enough  to  Increase  Achievement  Among  the  Poor?  Evidence  From  the  Harlem  Children’s  Zone”,  Working  Paper  No.  15473  (NBER,  Cambridge,  MA)    Dobbie,  Will  and  Fryer,  Roland  G.  (2011b),  “School  Characteris=cs  and  Student  Achievement:  Evidence  from  NYC  Charter  Schools”,  Unpublished  Manuscript  (Harvard  University).    Heckman,  James  J.,    Seong  Hyeok  Moon,    Rodrigo  Pinto,  Peter  A.  Savelyev,  and  Adam  Yavitz,  “The  Rate  of  the  Return  to  the  HighScope  Perry  Preschool  Program”,  Journal  of  Public  Economics,  94:  114–128,  (2010).    Heilig,  Julian  V.  and  Linda  Darling-­‐Hammand  (2008),  “Accountability  Texas  Style:  The  Progress  and  Learning  of  Urban  Minority  Students  in  a  High-­‐Stakes  Tes=ng  Context”,  Educa&onal  Evalua&on  and  Policy  Analysis,  30(2):  75-­‐110.    Jacob,  Brian  A.  (2005),  “Accountability,  incen=ves  and  behavior:  the  impact  of  high-­‐stakes  tes=ng  in  the  Chicago  Public  Schools”,    Journal  of  Public  Economics    89:  761-­‐796.    Krueger,  Alan  B.  (2003)  ,  “Economic  Considera=ons  and  Class  Size,”  The  Economic  Journal,  113,  F34—F63.