The Social Impact Monitoring and Vulnerability Assessment (SIMVA) 2018 survey was undertaken by the Mekong River Commission (MRC) Secretariat with field surveys implemented by Member Countries. The SIMVA 2018 followed the methodology of the SIMVA 2011 baseline survey and the SIMVA 2014 survey on shocks and trends. The SIMVA 2018 survey primarily builds on these two previous exercises and aims to set a technical framework for decentralized SIMVA field data collection, with the expectation that responsibility will rest fully with Member Countries by 2033.