The Manchester School. 2020;88:531–555. wileyonlinelibrary.com/journal/manc | 531 © 2019 The University of Manchester and John Wiley & Sons Ltd Received: 16 January 2019 | Revised: 26 October 2019 | Accepted: 18 November 2019 DOI: 10.1111/manc.12308 ORIGINAL ARTICLE Assessing the performance of Spanish secondary education institutions: Distinguishing between transient and persistent inefficiency, separated from heterogeneity Manuel Salas-Velasco Department of Applied Economics, University of Granada, Granada, Spain Correspondence Manuel Salas-Velasco, Department of Applied Economics, University of Granada, 18071 Granada, Spain. Email: msalas@ugr.es Abstract This paper evaluated the performance of Spanish secondary schools whose 15-year-old students were assessed in mathe- matical competencies by the OECD (PISA program) in 2003 and 2012. The technique employed was the stochastic fron- tier analysis for panel data using a sample of schools which participated simultaneously in both waves. First, the para- metric measurement of time-varying technical inefficiency was done in this paper using three standard models. Second, we used the four random component stochastic frontier model proposed by Kumbhakar, Lien, and Hardaker [2014. Journal of Productivity Analysis, 41(2), 321–337] that dis- tinguishes between residual or transient technical ineffi- ciency and persistent technical inefficiency, separated from heterogeneity. Persistent (time invariant) inefficiency was a larger problem than residual (time varying) inefficiency when evaluating the educational performance of Spanish secondary schools over time. Finally, we introduced the re- cent model recommended by Badunenko and Kumbhakar [2017. European Journal of Operational Research, 260(2), 789–803] to accommodate heteroscedasticity associated with both heterogeneity and the noise terms, incorporat- ing at the same time determinants of both persistent and time-varying inefficiency. School inefficiency was presum- ably not caused by something unexpected within each year such as greater difficulty in hiring teachers, but rather by