The level of imports of wood-based products at high risk of illegality was estimated through an evaluation of product flows. The evaluation involved estimating the RWE volume and value of imports (in US dollars) from official import data for each year as well as the bilateral flow of each category of wood-based product. Those values were then multiplied by estimates of the proportion that was likely to be illegal. That proportion was based on an estimate of the level of illegality likely to be associated with the export of each product category for a given country and year as well as the extent to which importing countries demonstrate a preference for legal (e.g. FSC-certified) products.