Traditional literature on sampling techniques focuses mainly on statistical samples and covers non-random (non-statistical) samples only marginally. Nevertheless, there has been a recent revival of interest in non-statistical samples, given their widespread use in certain fields like government...

The quality of the geographical breakdown in the balance of payments and related statistics (such as international trade in goods, trade in services and foreign direct investment (FDI) statistics) can be assessed by means of comparisons with mirror data in order to assess bilateral asymmetries....