The poverty level is the minimum level of income which is deemed adequate in a particular area. Such calculations should occur for every county, since there is often a significant variation in the cost of living between counties. The poverty level for a single person (household size of one) should be defined as an income at or less than the negative 1.75 standard deviation of the income of the county average. The same calculation should occur for each size of household. This would mean that right around 4% of the population of any county would be defined as having income at or below the poverty level.