A class of deviations from rank-size regularity: Three interpretations

Abstract

Parr J.B. (1976) A class of deviations from rank-size regularity: three interpretations, Reg. Studies 10, 285–292. The rank-size distribution has been widely used to summarise the size structure of urban systems. Such a distribution yields a downward-sloping straight line when cities are plotted by rank and size on logarithmic scales. However, it is frequently observed that the rank-size line is not straight but displays an alignment which is concave to the origin. Several interpretations of this type of deviation from rank-size regularity are examined. The first views the deviation as a modification of the forces which produce a rank-size distribution; the second and third interpretations treat such deviation as adherance to differing forms of the lognormal distribution.

Keywords:

• Rank-Size Concavity
• Simon Model
• Law of Proportionate Effect
• Lognormal
• Truncation
• Threshold Parameter