Category Archives: rank size

Urban Clusters and Agglomeration

A new paper from our group. Click here for the paper and also for the issue of Environment and Planning B .

Abstract: Agglomeration economies are a persistent subject of debate in regional science and city planning. Their definition turns on whether or not larger cities are more efficient than smaller ones. Here, we complement existing discussions on agglomeration economies by providing a sensitivity analysis of estimated externalities to the definitions of urban agglomeration. We regress wages versus population and jobs over thousands of different definitions of cities in France, based on an algorithmic aggregation of spatial units. We also search for evidence of larger inequalities in larger cities. This paper therefore focuses on the spatial and economic complexity of the mechanisms defining agglomeration within and between cities.

City size: Spatial dynamics as temporal flows


Robin Edwards and myself have improved our visualisation of city size and rank over time and this is now published as a featured graphic in Environment and Planning A in their forthcoming material. It is quite hard to represent three variables in a two-dimensional plot but here Robin and myself use an alluvial diagram similar to a Sankey-type diagram to achieve this which we think encapsulates rather well the way in which cities change not only their rank but also their size over time. Rank and time are unidimensional, integer quantities in our representation while size is continuous volumetric and the graphic we have used captures this rather nicely. I have posted bits of this before but if you click on this link you will get the forthcoming graphic which is in fact free currently at the journal web site. Have a look at our two previous posts to full in all the detail about this. Enjoy

City Rank and Size Dynamics

Visualising Ranks and Size in Space and Time

Optimal Cities, Ideal Cities


Ideal Cities, such as Frank Lloyd Wright’s Mile High Tower The Illinois (pictured here), and Le Corbusier’s City of Tomorrow have fallen out of fashion in recent years. But the rise of the smart city and the notion of the instrumented district together with our current concern for Future Cities is beginning to resurrect such theories. The current editorial (click here here) in Environment and Planning B deals with these ideas and inquires into the optimal size for such ideal cities. In fact the ideal city and its close economic comparator the optimal city are long-standing issues that I discuss in this short note with respect to questions of how we measure such optimality. There are two main approaches. The oldest is the visual approach – ideal cities tend to be geometric purities – as developed at their pinnacle during the Italian Renaissance while the second is concerned with optimal city size – optimal populations – that range from Plato’s 5040 to Ebenezer Howard’s ideal garden city of 30000 to Le Corbusier’s City of Tomorrow at 3 million. I deal with some of these issues in this editorial but the question of how all this relates to the smart city is something that I do not discuss. I will blog about it soon. I also need to note that the journal in which this editorial is published is now owned by Sage and the journal’s new web site with its contents including the editorial are here.