matched by the Kernel method. In special, the coefficients related to Higher Education in Portuguese on Portuguese scores become all statistically non-significant.

In summary, the results indicate that the increase in Teacher Higher Education in Portuguese that occurred in _Treated_ 3 and _Treated_ 4 schools (most intensively treated schools) may have positively affected students’ Portuguese scores, but that this result is not robust to schools’ participation restriction on ENEM. Also, the increase in Teacher Higher Education seems to have positively affected students’ math scores of _Treated_ 2,3 schools (those whose indicator was below 73.3% in 2009 and raised above 87.5% in 2015). For these schools, whose indicator was below 73.3% [or 45.8%, on average] in the year 2009 and has risen above 87.5% [or 99.2%, on average] in the year 2015, the estimated _ATT_ is between 4.2 and 4.5 points in math exam, what implies in an mean increase between 0.079 and 0.084 points for every 1 percentage point in Percentage of Math Classes Taught by Teachers with Higher Education.

Table 12 presents a summary of the so called _negative_ Treatment Effect, also estimated from Equation (1) controlling by the same set of characteristics for both the whole sample and matched samples. Again, the estimated results on the paired samples are statistically non-significant, except for the effect on Portuguese scores of school in Treatment group 2 in relation to the Percentage of Portuguese Classes Taught by Teachers with Higher Education in Portuguese, whose coefficient is positive and significant at 10% significance only when considering the sample matched by Radius method.

Table 12 – Estimates of _Negative_ Treatment Effects on Mathematics and Portuguese Scores

||||All schools<br>||Participati|on restriction<br>|on schools<br>|
|---|---|---|---|---|---|---|---|
|Teachers<br>education|Treatment<br>group|No<br>matching<br>(1)|Radius<br>matching<br>(2)|Kernel<br>matching<br>(3)|No<br>matching<br>(4)|Radius<br>matching<br>(5)|Kernel<br>matching<br>(6)|
|||<br>|<br>_Math sc_<br>|<br>_ores_<br>|<br>|<br>|<br>|
||Treated 1|-2.025|-1.400|-1.427|1.740|1.719|1.943|
|Hih|Treated 2|-1.078|-0.539|-0.713|-0.625|-0.436|-0.397|
|ger<br>education|Treated 3|2.305|2.539|2.211|3.053|4.491|4.342|
||Treated 2,3|0.770|0.566|0.609|1.026|0.634|0.660|
||Treated 1,2,3|-0.835|-0.163|-0.102|0.492|1.026|0.891|
||Treated 1|-1.135|-1.635|-1.557|0.495|0.213|0.219|
||Treated 2|-0.732|-0.439|-0.508|0.371|0.628|0.663|
|Higher<br>dtin in|Treated 3|0.594|1.891|1.786|0.465|1.798|1.899|
|eucao<br>Math|Treated 4|-2.893|-2.424|-2.254|1.251|1.074|0.690|
||Treated 2,3,4|0.121|0.786|0.791|1.276|1.760|1.712|
||Treated 1,2,3,4|-0.483|-0.487|-0.533|1.211|1.148|1.225|
||||_Portugues_|_e scores_||||
||Treated 1|-0.0589|0.295|0.0774|0.894|1.324|1.181|
|Hih|Treated 2|1.019|0.129|-0.0246|2.362|2.961|2.773|
|ger<br>education|Treated 3|0.732|0.166|0.563|3.774|1.229|1.254|
||Treated 2,3|0.128|-1.100|-1.049|4.026|2.037|2.016|
||Treated 1,2,3|0.378|-0.650|-0.605|4.244**|3.630*|3.523*|
||Treated 1|-2.463*|-1.198|-1.251|-2.070|-2.225|-1.714|
||Treated 2|1.661|2.398*|2.079|0.359|0.686|0.763|
|Higher<br>di i|Treated 3|0.0466|-0.303|-0.387|1.544|1.498|1.840|
|eucaton n<br>Portuuese|Treated 4|4.105**|1.246|2.310|3.090|2.542|2.011|
|g|Treated 2,3,4|1.008|0.292|0.274|0.233|-0.227|-0.375|
||Treated 1,2,3,4|-0.136|-0.0840|-0.355|-0.123|-0.595|-0.537|

_Note._ School level Fixed Effects Model with linear trends by UF (omitted). Covariates were omitted. Cluster-robust standard errors in parentheses. *Statistically significant at 10% significance level. **Statistically significant at 5% significance level. ***Statistically significant at 1% significance level.

After restricting the sample by participation in ENEM exam, the only statistically significant coefficients are those related to the effect of the decrease in Teacher Higher Education on _Treated_ 1,2,3 schools scores in Portuguese (schools whose indicator was above 72.7% in 2009 and dropped to below 72.7% in 2015). These schools seem to have benefited from the reduction in the percentage of higher educated teachers in the period, which may reflect a strategy of exchanging higher educated but lower performance teachers by newer teachers, who perform better despite the lower schooling.

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