On the importance of linking inputs and outputs in material flow accounts. The Weight of Nations report revisited

The influential Word Resources Institute report The Weight of Nations of 2000 called for additional research effort to understand linkages between primary material inputs and output of waste and emissions in material flow accounts. The report proved highly influential in driving efforts toward methodological harmonization of national material flow accounts but had little impact in triggering additional study into comprehensive material flow accounts and material balances for national economies. In this research we test the feasibility of linking inputs to outputs by establishing material flow balances for five countries including Germany, Japan, the United States, China and Australia using available statistical data and agreed calculation methods. While statistics for emissions to air are well documented, statistics for solid waste are usually incomplete and for many countries are of poor quality. We employ stock and flow modeling to determine the “waste potential” of a national economy, which can be used to validate statistically reported waste flows. We ask whether the accounts could be up-scaled to a global dataset and discuss challenges and limitations of such an approach; we also revisit the findings of the WRI report and find that methodological improvements to material flow accounting yield more reliable results than could be achieved two decades ago. Unifying input and output accounts in one coherent framework, i.e. a material balance, allows alignment of the policy domains of resource efficiency, greenhouse gas and pollution abatement, and waste minimization.