Counterfactual Planning

Abstract

This article uses a specific and long-established planning policy, Seoul's greenbelt, to explore the concept of counterfactual planning. Suppose the greenbelt had never existed. How would the spatial structure of the metropolitan region have been different? Under both monocentric and polycentric assumptions, both population and employment (in terms of densities and numbers) would have been much lower in the core city and the periphery. The effects would have been more dramatic in the core city, suggesting that the greenbelt contributed significantly to densification and congestion. Still, its consequences for leapfrog development were far from negligible. In addition, because the greenbelt policy was reinforced by a strong government strategy to build very large new towns beyond the greenbelt, a significant jobs-housing imbalance resulted because people decentralized much faster than jobs. Whether these effects are offset by the recreational and other environmental benefits of the greenbelt is unclear.

What if Beijing had enforced the 1st or 2nd greenbelt? – Analyses from an economic perspective

“…Scenario N1-S2 shows that a large and wide greenbelt performs better in containing population and jobs within the designated greenbelt boundary. This finding is different from the findings in Bae and Jun (2003) and Freestone (2002), as their research has shown that the greenbelts decentralised population to places beyond the greenbelts while confining jobs in the city centre, which caused a jobs-housing imbalance. The situation in Beijing is different, because without transport improvements, economic activities would not be diverted to new towns easily and a wide greenbelt would still cause overconcentration in the main city.…”

“…This indicates that the planned greenbelts would bring some negative economic impacts to the city, including decreasing productivity, decreasing household utility, and concentrating residents in the expensive city centre. The effects of increasing population and employment density in the city centre were also found in research done by Bae and Jun (2003) and other studies. For example, Hall (1974) and Evans and Hartwich (2006) found that London's greenbelt increased population density in the main city which pushed housing prices up.…”

“…Based on the historic counterfactual idea, Bae and Jun (2003) Inspired by the idea of counterfactual history, we build a general spatial equilibrium model and put it into a recursive modelling framework as done by Jin, Echenique and Hagreaves (2013). In this framework, the spatial equilibrium model explores the interactions amongst the labour market, product market, and the housing and business floorspace market.…”

The Effects of Releasing Greenbelt Restrictions on Land Development in the Case of Medium-Sized Cities in Korea

“…Some researchers agree that the GB policy results in a spatial concentration of development in core cities, and higher densities [30][31][32]. Other researchers, in contrast, have pointed out that the GB brought about leapfrog development by shifting urban development beyond the GB area [10,21,22,33,34]. Unlike the UGB, development in GB lands is strictly prohibited.…”

“…In the absence of the greenbelt policy, the land-use change between 2000 and 2017 can be estimated through various modelling approaches. Most studies measure the effect of an urban containment policy with a greenbelt dummy variable in a regression model [34,39]. For example, Bae and Jun [34] estimate the population and employment density gradients with a greenbelt dummy variable in their model to reallocate jobs and workers in order to measure the effects of Seoul's greenbelt on commuting costs.…”