Abstract
This paper aims to explain the low performance of Brazil in PISA 2015, exploring innovations in the organization of the exam and introducing the effect of a break amidst an exam. We show that Brazilians have a performance decline throughout the exam and propose an alternative measure to the decay from a discontinuity in scoring chance between the break. Decay and discontinuity are plausible measures for differences in non-cognitive abilities. We argue that decay may be the result of students spending too much time on initial questions and not reaching the latter. Despite poor performance in non-cognitive indicators, Brazilian performance is mainly explained by the difficulty in initial questions, highlighting a disadvantage in cognitive abilities in relation to other countries.