Primacy analysis of the system of Bulgarian cities

TL;DR

This paper analyzes the primacy in the Bulgarian urban system over different periods, introducing new indices to improve upon existing measures and providing numerical illustrations to understand urban dominance patterns.

Contribution

It introduces new indices to measure primacy, addressing limitations of existing indices like Sheppard, and applies them to Bulgarian cities over extensive time periods.

Findings

Primacy patterns vary over time and between city systems.

New indices provide more accurate assessments of urban dominance.

Numerical illustrations clarify the primacy dynamics.

Abstract

We study the primacy in the Bulgarian urban system. Two groups of cities are studied: (i) the whole Bulgaria city system that contains about 250 cities and is studied in the time interval between 2004 and 2011; and (ii) A system of 33 cities, studied over the time interval 1887 till 2010. For these cities the 1946 population was over $10\ 000$ inhabitants. The notion of primacy in the two systems of cities is studied first from the global primacy index of Sheppard [$^1$]. Several (new) additional indices are introduced in order to compensate defects in the Sheppard index. Numerical illustrations are illuminating through the so called "length ratio".