The minimum population needed to justify the provision of a certain good or service. This may be expressed crudely, in population numbers, but purchasing power may be a better yardstick for commercial goods or services. Note that threshold populations may vary regionally, and certainly vary nationally; the threshold population for a baker’s shop is far lower in France than in the UK, for example. The actual evaluation of the threshold population for most goods and services is difficult. However, Coon and Leistritz (2002) North Dakota State U., Agribus. & Appl. Econ. Misc. Rept 191 have, with many caveats, attempted to do so.