Since 1993，the International Energy Agency（IEA）has provided medium to long-term energy projections using the World Energy Model（WEM）.The model is a large-scale simulation model designed to replicate how energy markets function and is the principal tool used to generate dctailcd sector-by-sector and region-by-region paojcetions for the World Energy Outlook（WEO）scenarios.由此可知World Energy Model是由（）开发的。