BEA's estimates of the space economy are prepared within an economic accounting framework that is fully consistent with the framework used to produce U.S. gross domestic product (GDP). This framework also underpins the estimates of BEA's other “satellite accounts,” such as that for arts and cultural production and for travel and tourism. Industry economic impact reports related to the space economy use different economic measurement concepts from the SESA and use different definitions of the “space economy,” so their estimates are expected to differ from those presented here. For example, industry economic reports often reflect revenue values for space-related companies or space-related products. Although revenue relates closely to BEA's gross output measure, there are significant differences between the two concepts. In addition to revenue, gross output also includes commodity taxes, other operating income, and inventory change. The different measures and differing definitions make it difficult to make direct comparisons between the various industry economic impact reports and the SESA estimates.