This report discusses AERO's 2022 analysis of student writing data -- the most extensive investigation into this area ever conducted in Australia. AERO's researchers analysed more than 10 million NAPLAN writing results, spanning 2011 to 2021, and 366 samples of students' NAPLAN writing. Overall, our research suggests that students' writing skills have declined over 7 years (2011 to 2018), with many high school students significantly behind the expectations outlined in curriculum documents. The key findings, implications and a series of recommendations are presented in both the full report and report summary document. [AERO acknowledges that this publication was made possible by the joint funding it receives from Commonwealth, state and territory governments.]