Assessing geographical effects in spatial diffusion processes: The case of euro coins

in Computers, Environment and Urban Systems (2017), 61

We examine how geographical structures impact diffusion processes within a regional system. From the example of euro coin diffusion across countries, we show how the relative position and population ... [more ▼]

We examine how geographical structures impact diffusion processes within a regional system. From the example of euro coin diffusion across countries, we show how the relative position and population endowment of regions impact our understanding of interregional mobility, beyond simple spatial interaction effects. The mix of coins of different origins is a complex but unique trace of the movement of individuals within a common currency area, potentially revealing a new facet of European integration. We simulate an individual-based dynamic model where agents move and exchange coins across regions. We analyse the convergence towards a homogeneous mix of coins through time for a series of different theoretical spatial systems. This sensitivity analysis demonstrates the impact of the regularity and aggregation levels, or centrality/periphery effects, on spatial diffusion dynamics. We then calibrate the model against empirical data for the regions of 5 European countries and provide estimates of mobility rates, distance decay and population attractiveness factors, affecting the diffusion of coins, hence international movements and European integration. [less ▲]

Greener and larger neighbourhoods make cities more sustainable! A 2D urban economics perspective

in Computers, Environment and Urban Systems (2015), 54

We analyse urban growth forms by means of a 2D microeconomic model where households value green space at neighbourhood scale. We analytically demonstrate that cities can grow more densely when households ... [more ▼]

We analyse urban growth forms by means of a 2D microeconomic model where households value green space at neighbourhood scale. We analytically demonstrate that cities can grow more densely when households have the possibility to enlarge the neighbourhood in which they value green space, thus emphasizing the importance of neighbourhood planning in particular for facilitating short trips and views of green amenities. We also show by simulation that the size and form of the city, relative to the size and form of neighbourhoods, impact on the decision of households to leapfrog land or not, thus impacting on the emergence of scattered urbanisation patterns. We conclude that carefully addressing the spatial arrangement of green space and buildings and facilitating trips within neighbourhood units constitute an effective policy lever and an attractive way to deliver more sustainable cities. We further argue that our theoretical experiment with complementary analytical and computer-based simulation provides micro-economic reasoning to the main elements of the Garden City and neighbourhood unit planning concepts. [less ▲]

Urban compactness and the trade-off between air pollution emission and exposure: Lessons from a spatially explicit theoretical model

in Computers, Environment and Urban Systems (2014), 45

Air pollution is a major concern in urban areas worldwide. The interplay between urban structure and air pollution from an environmental, health and social perspective is the focus of our work: we model ... [more ▼]

Air pollution is a major concern in urban areas worldwide. The interplay between urban structure and air pollution from an environmental, health and social perspective is the focus of our work: we model how urban structure impacts traffic-induced pollutant emissions and the exposure of residents to those pollutants. We present a chain of models applied to theoretical monocentric space: a residential choice model with endogenous open-space and road network, a commuting traffic generation and road assignment model and a pollutant emissions, dispersion and exposure model. The theoretical study approach decouples results from location specific characteristics and enables us to analyse how the preference of households for green amenities, a transport tax, the provision of public transport alternatives and local neighbourhood design impact the environment (total emissions) as well as residents’ health (population exposure) and utility. We emphasise that environmental strategies in the form of urban compaction have a strong impact on the exposure of households to pollutants, especially close to the centre, in addition to their reduction of welfare. Our results suggest that more beneficial policy outcomes can be obtained from strategies which preserve green spaces close to the centre or which intend a greater shift from car to public transport. Further, we find indication that different local designs of neighbourhoods have much stronger impacts on the exposure–emission tension than city-wide land use or transport options. [less ▲]