Economy-wide material flow accounts (EW-MFA) is a framework to compile statistics linking flows of materials from natural resources to a national economy. EW-MFA are descriptive statistics, in physical units such as tonnes per year. EW-MFA is consistent with the principles and system boundaries of the United Nations System of National Accounts (SNA) and follows the residence principle. This means that EW-MFA is also a part of the System of Integrated Environmental and Economic Accounting (SEEA).