The International Labour Office (ILO) is looking for an individual to undertake work as an External Collaborator. Below is a summary of the work to be performed: The consultant will support the ILO’s work on the development, review, and quality assurance of methodologies and estimates relating to state-imposed forced labour within the framework of the Global Estimates of Modern Slavery (GEMS). The assignment will focus on assessing methodological frameworks, reviewing case classifications and typologies, evaluating estimation assumptions, and strengthening the evidence base underpinning national and global estimates. The consultant will contribute to the identification of potential gaps in case coverage, assess whether candidate cases meet relevant definitional and evidentiary thresholds, and review the quality, reliability, and appropriateness of secondary, documentary, administrative, and other data sources used in the estimation process. The assignment will also involve providing technical feedback on estimation outputs, supporting methodological documentation, participating in technical consultations and peer reviews, and developing recommendations to enhance the rigor, consistency, and credibility of future state-imposed forced labour estimation exercises in line with international labour standards.