To test this, we first check the extent to which the matched 75% sample is different from the main sample. Table 6 shows balance tests for the matched sample, for pre-treatment covariates and for the classroom observation variables collected at baseline. The balance is quite similar to the baseline sample. Treatment and control schools present some differences in enrollments, proportion of female teachers, student-teacher ratio, classroom management activities, instructional activities with all students engaged, and students offtask, but a joint test for the joint significance of the variables in predicting treatment fails to reject that they are jointly equal to zero, supporting that the randomization is balanced for this subsample. <u>Table 6: Pre-treatment covariates and classroom dynamics balance - Matched sample</u>

|Covariat|es|||Classroom|Dynamics|||
|---|---|---|---|---|---|---|---|
||Control<br>Means|Treatment<br>Means|Difference||Control<br>Means|Treatment<br>Means|Difference|
|2013 Covariates||||||||
|Portuguese proficiency|257.4|260.6|-3.209|Instructional activities|0.655|0.674|-0.0192|
||[18.78]|[22.45]|[2.492]||[0.117]|[0.108]|[0.0134]|
|Mathematical proficiency|268.4|272.2|-3.799|Classroom management activities|0.252|0.226|0.0257*|
||[22.65]|[29.51]|[3.178]||[0.0838]|[0.0859]|[0.0102]|
|High School enrollment|680.8<br>|581.0<br>|99.80*<br>|Off-task activities|0.0930<br>|0.0995<br>|-0.00651<br>|
||[350.8]|[324.9]|[40.34]||[0.0725]|[0.0702]|[0.00853]|
|High school enrollment - vocational|49.28<br>|69.40<br>|-20.11<br>|Student off-task|0.0387<br>|-0.247<br>|0.286*<br>|
||[138.8]|[153.7]|[17.59]||[1.089]|[1.012]|[0.125]|
|Rural Area|0.0385|0.0596|-0.0211|Instructional activities with all|-0.0323|0.236|-0.268*|
||[0.193]<br>|[0.238]<br>|[0.0261]<br>|students engaged|[1.071]<br>|[1.105]<br>|[0.130]<br>|
|Pass rate|85.00|85.42|-0.412|Reading aloud|0.0477|0.0423|0.00543|
||[9.568]|[10.45]|[1.202]||[0.0525]|[0.0424]|[0.00567]|
|Failure rate|6.172|6.117|0.0551|Demonstration/Lecture|0.325|0.337|-0.0119|
||[5.058]|[5.273]|[0.619]||[0.127]|[0.129]|[0.0153]|
|Dropout rate|8.825<br>|8.466<br>|0.358<br>|Discussion/Debate/Q&A|0.0978<br>|0.0976<br>|0.000239<br>|
||[6.789]|[6.570]|[0.798]||[0.0656]|[0.0773]|[0.00863]|
|Students per class|34.30|33.95|0.343|Practice & Drill|0.00375|0.00543|-0.00168|
||[4.978]|[5.308]|[0.617]||[0.00933]|[0.0147]|[0.00150]|
|Female principals|0.477|0.510|-0.0330|Assignment/Class work|0.120|0.133|-0.0138|
||[0.501]|[0.502]|[0.0600]||[0.0919]|[0.100]|[0.0115]|
|Experience as a principal (> 10 years)|0.515|0.510|0.00545|Copying|0.0612|0.0587|0.00250|
||[0.502]|[0.502]|[0.0600]||[0.0481]|[0.0453]|[0.00558]|
|Principal with graduate degree|0.992<br>|0.993<br>|-0.00107<br>|Verbal Instruction|0.0635<br>|0.0571<br>|0.00646<br>|
||[0.0877]|[0.0814]|[0.0101]||[0.0427]|[0.0384]|[0.00484]|
|Female teachers|0.568<br>|0.515<br>|0.0526*<br>|Discipline|0.0200<br>|0.0163<br>|0.00371<br>|
||[0.181]<br>|[0.185]<br>|[0.0219]<br>||[0.0194]<br>|[0.0193]<br>|[0.00231]<br>|
|Temporary teachers|0.994|0.994|0.000665|Classroom management|0.0823|0.0789|0.00335|
||[0.0158]|[0.0196]|[0.00215]||[0.0580]|[0.0478]|[0.00631]|
|Teacher's age|35.29|30.16|5.131|Classroom management alone|0.0862|0.0740|0.0122|
||[26.10]|[68.33]|[6.360]||[0.0653]|[0.0555]|[0.00721]|
|Experience as a teacher (>10 years)|0.821|0.813|0.00724|Social interaction|0.0152|0.0180|-0.00275|
||[0.0859]|[0.0878]|[0.0104]||[0.0260]|[0.0315]|[0.00348]|
|Low salary (< 2m.w.)|0.193<br>|0.184<br>|0.00940<br>|Teacher out of the room|0.0558<br>|0.0576<br>|-0.00178<br>|
||[0.145]|[0.156]|[0.0180]||[0.0478]|[0.0498]|[0.00585]|
|High Salary (> 5 m.w.)|0.219|0.191|0.0287|Teacher uninvolved|0.0220|0.0239|-0.00198|
||[0.186]|[0.180]|[0.0219]||[0.0371]|[0.0353]|[0.00432]|
|Mother's education < middle school|0.490|0.489|0.000752|No material|0.129|0.131|-0.00210|
||[0.0978]|[0.111]|[0.0125]||[0.0894]|[0.0761]|[0.00988]|
|Mothers with graduate degree|0.0558|0.0544|0.00141|Textbook|0.105|0.0924|0.0123|
||[0.0283]|[0.0305]|[0.00353]||[0.102]|[0.0922]|[0.0116]|
|2014 Covariates||||Notebook|0.121|0.130|-0.00891|
|Portuguese proficiency|253.0|256.3|-3.289||[0.0799]|[0.117]|[0.0121]|
||[17.84]|[20.45]|[2.308]|Blackboard|0.271|0.276|-0.00472|
|Mathematical proficiency|254.0<br>[21.88]|258.9<br>[27.00]|-4.931<br>[2.963]|Learning aides|[0.132]<br>0.0233|[0.124]<br>0.0231|[0.0152]<br>0.000184|
|Age-Gradedistortion|3102|3089|0139||[00503]|[00400]|[000539]|
||.<br>[13.75]|.<br>[14.92]|.<br>[1.722]|TIC|.<br>0.0609|.<br>0.0702|.<br>-0.00925|
|Proportion of students per teacher|0.0532<br>[00143]|0.0582<br>[00208]|-0.00497*<br>[000217]|Cooperative|[0.0901]<br>000878|[0.0872]<br>000904|[0.0106]<br>-0000253|
|Proportion of black and brown teachers|.<br>0.282|.<br>0.301|.<br>-0.0197||.<br>[0.0263]|.<br>[0.0308]|.<br>[0.00345]|
||[0242]|[0232]|[00283]|||||
|Proportion of black and brown students|.<br>0.607|.<br>0.611|.<br>-0.00392|||||
||[0.214]|[0.228]|[0.0265]|||||
|Joint test (p-value) - All Variables|||0.34||||0.63|
|Joint test (p-value) - Only proficiency varia<br>|bles<br>||0.41<br>|||||
|Joint test (p-value) - Other variables exclu|ing proficie|ncy|0.44|||||
|Number of schools|130|151|||130|151||

_Note:_ Numbers in parentheses are standard deviations in the column of means and standard errors in columns of differences. * p<0.05 ** p<0.01 *** p<0.001 16