Net national income (NNI) per capita is the best indicator for comparing economic well‐being across countries available in the System of National Accounts (SNA). NNI is defined as gross domestic product (GDP) plus net receipts of wages,
salaries and property income from abroad, minus the depreciation of fixed capital assets (dwellings, buildings, machinery, transport equipment and physical infrastructure) through wear and tear and obsolescence. Estimates of NNI per capita, however,
are subject to greater uncertainties than those associated to GDP per capita, the most widely used indicator of national income. Uncertainties exist because of difficulties in measuring international income flows and capital depreciation.