Does Zipf's law hold for primate cities? Some evidence from a discriminant analysis of world countries

Largest cities of countries do not always follow Zipf's Law, generally 'obeyed' by smaller localities. In an attempt to analyze factors which may drive major cities of nations away from the 'rank-size' trend line stipulated by Zipf's Law, we investigated the population size gap between the first and second cities of 177 countries worldwide. According to our findings, high development levels are likely to reduce this gap, while the first city being the national capital is likely to widen the gap between the largest city and its 'nearest neighbor' in the national rank-size hierarchy.