Background: Teachers in developing countries face a complex challenge at work--teaching students who are first-generation learners, in classrooms with wide heterogeneity in learning levels, and in frequently resource-poor settings (Muralidharan et al., 2019; World Development Report, 2018). The presence of many of these potentially binding external constraints might suggest to teachers that their effort matters little in influencing student learning, leading to a perception of low returns to effort. These beliefs could be reinforcing if teachers invest less effort, observe low returns and then update their beliefs. This hypothesis is supported by cross-country studies that document a widespread consensus among teachers that 'there is little they can do to help a student learn if parents are uneducated, or have personal or financial problems' and that 'a student's home environment directly limits the influence of their teaching' (Sabarwal et al., 2022; Young Lives, 2016-17). From a policy perspective, it is unknown whether teachers' beliefs about returns to effort are malleable and can be influenced through targeted interventions. This idea has been extensively studied in the psychology and education literatures under the theoretical frames of teacher locus of control and teacher efficacy (Rose and Medway, 1981; Gibson and Dembo, 1984, Tschannen-Moran et al., 1998), however, it is unclear whether these constructs can be used as a policy level to impact student learning at scale, especially in the context of developing countries. The question is even more relevant in a post-covid context where learning lags are likely to adversely impact classroom environments and strain psychological reserves of teachers, in the absence of adequate support and resources. Research Question: In this project, I examine the extent to which beliefs about perceived control over the parameters of education production function influence the choice of teacher effort and impact student learning. The research aims to answer the following questions: (a) To what extent are teachers' beliefs about perceived control malleable through exposure to a psychosocial intervention? (b) What is the causal impact of perceived control beliefs on teachers' effort levels and students' academic outcomes? The study's main hypothesis is that using a psychosocial intervention grounded in positive psychology and behavioral science, shifts teachers' perceived control over education production, increases teachers' effort in the classroom and improves student learning in Math. Research Design: To study these questions, I conduct a randomized controlled trial with 83 schools in a large school chain in north India. An experimental design allows me to exogenously manipulate teacher beliefs to examine malleability and enables me to isolate the effect of beliefs on other outcomes. Randomization is done at the school-grade level. Each teacher is mapped to a unique school-grade. I conduct pairwise randomization across all possible grade pairings within schools. With this design, the study is well-powered to detect effects at the student- and teacher-level, in line with related work. Setting: The study is conducted in a large rural school chain of 129 schools in northern India. The private school chain is run by a charitable trust and provides high-quality and subsidized education to rural populations. Participants: The study sample consists of teachers and students in grades 2, 4, 6, and 8 across 83 schools, comprising 292 teachers and around 5,600 students. I work with non-adjacent grades within each school to minimize the possibility of spillovers across adjacent grades. Intervention: I use an evidence-backed psycho-social intervention that has been implemented by McKelway (2021) in a similar context outside education. The intervention targets perceived control through two approaches -- a skill-building approach that enhances self-efficacy, and a control-enhancing approach that develops an internal locus of control. The modules are crafted to use cognitive restructuring strategies and use contextualized stories about role-models, motivational quotes and affirmations that highlight primary and secondary forms of control. Teachers undergo five weeks of online training for two hours each week, with a main session, a debrief session, and a weekly assignment to reinforce concepts. The training is conducted after school hours to minimize disruption to the school timetable. To minimize the scope for demand effects, the curriculum is purged of any references to teaching skills or classroom practices. Teachers in the treatment arm are exposed to psychological content covering five topical areas -- character strengths, self-efficacy, emotion-management, goal-setting, and problem-solving. Teachers in the placebo arm received training of a similar duration and format but with psychologically inactive content. Data: I collect data through 4 rounds of primary data collection -- at baseline, immediately after, three and six months after the intervention. Multiple endline rounds enable a rich description of the persistence of impact. I collect primary data on teachers' beliefs and efforts through interviews and classroom observations. I access data on school- and student-level characteristics from school administrative records. To measure teachers' beliefs, I use a novel experimental task using a multiple price list approach to credibly elicit teachers' perceived control beliefs about improving performance of students in the bottom tail of ability distribution. The study's secondary analyses investigate mediating variables and alternative channels through which the intervention might impact teacher and student outcomes. Findings: The study is currently in field with an ongoing last round of endline data collection. Preliminary results indicate balance on observable characteristics at baseline and a positive impact on perceived control beliefs as measured by the multiple price list task immediately after the intervention. Analysis on teacher effort and student learning outcomes, as well as on later measures is ongoing, and will be available by the time of the conference. Conclusion: The need to raise learning outcomes among students in the developing world has spurred a range of education initiatives. Governments spend millions of dollars in providing in-service teacher training even though evidence suggests limited productivity of these investments. This raises a need to find training models that address core teaching challenges and are effective at scale. This project holds promise to show important evidence about efficacy of a novel psychosocial intervention that can be scaled up in relevant settings.