Double accounting in energy footprint and related assessments: How common is it and what are the consequences?

Highlights: • Overview of energy extensions in multi-regional input-output (MRIO) analysis. • Review of MRIO-based energy assessments. • Identification of double accounting in MRIO-based energy assessments. • Quantification of how results are affected by double accounting. • Recommendations for energy extension producers and users. The number of input-output assessments focused on energy has grown considerably in the last years. Many of these assessments combine data from multi-regional input-output (MRIO) databases with energy extensions that completely or partially depict the different stages through which energy products are supplied or used in the economy. The improper use of some energy extensions can lead to double accounting of some energy flows, but the frequency with which this happens and the potential impact on the results are unknown. Based on a literature review, we estimate that around a quarter of the MRIO-based energy assessments reviewed incurred into double accounting. Using the EXIOBASE MRIO database, we also analyse the effects of double accounting in the absolute values and rankings of different countries' and products' energy footprints. Building on the insights provided by our analysis, we offer a set of key recommendations to MRIO users to avoid the double accounting problem in the future. Likewise, we conclude that the harmonisation of the energy data across MRIO databases led by experts could simplify the choices of the data users until the provision of official energy extensions by statistical offices becomes a widespread practice.