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 Article by Chang-Hee Christine Bae & Myung-Jin Jun 2003

1. Counterfactual
Planning
What if there had been no
Greenbelt in Seoul?
Chang-Hee Christine Bae & Myung-Jin Jun
Presented by : Prabal Dahal | 078MsUrP012 | 2022
Paper Review on:
Submitted to: Kirti K Joshi | PhD
2003
Journal of Planning Education and Research

2. 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.

3. Background
• The restrictions remained in place for thirty years
• The reform momentum was primarily initiated as a
response to a political problem created by the neglect
of the property rights of the “natives” (residents).
• The outcomes were the abolition of the greenbelts in
seven medium-sized cities (where they were never
binding constraints) and much more modest releases
of land in the seven largest cities, including Seoul and
Pusan.
• The main motivations for very modest changes are
environmental protection, the preservation of
recreational resources, and saving agricultural land.
• Land was classified into five grades (A to E), and
grades D and E were potentially released from the
greenbelt (Jin 2001).

4. Method
Data:
• employment and
population data from the
National Statistical Office
• greenbelt boundary maps
from the Korean Research
Institute for Human
Settlements and Seoul
Development Institute
• The administrative
boundaries and the
greenbelt boundaries were
embedded into a
geographic information
system (based on MapInfo)
and used to calculate
interzonal distances
• Transportation network
and trip flow data were
from the SDI
Monocentricity Analysis
Assumption
A closed-city model, that is, that the population
in each year (not between years) remains fixed
▪ Results of an earlier monocentric density gradient
analysis (Jun and Bae 2000) [above]
▪ Estimate of the commuter distance savings from
this reallocation to measure any “excess”
commuting costs associated with the greenbelt
(Hamilton 1982, 1989; Small and Song 1992).
Using standard urban economics model (e.g.,
Mills and Hamilton 1989), we can calculate the
distance from the center to the edge of the
urban area:
(Jun & Bae, 2000)
R is land rent; u is the radial distance from the CBD; N
is the metropolitan population; and E = (aBw^θ1)^–1,
where a is the land exponent in the production
function, B is a scale parameter, w is the wage, and
θ1 is the income elasticity of demand for land
Introducing inner and outer boundaries,
u1 and u2, respectively
Distance calculated by solving equation:

5. Monocentricity Analysis
Method
Population (or employment) density function with the
greenbelt
Using the function, calculation of intercept and slope of
population (or employment) density function for the
three types of zones: NGBCore (non greenbelt core), GB
(greenbelt), and NGBOR (nongreenbelt outer ring)
Assumed that 40 percent of the total land area in both the greenbelt and the
outer-ring, non-greenbelt area will be suitable for urban development
Results
Green Belt Scenario:
• The greenbelt extends from 14 to 25 km from CBD
• Metropolitan boundaries for population and
employment = 61 and 57 km, respectively, from
the CBD
Non- Green Belt Scenario:
• Boundaries shrink to 42 km for both population
and employment
• There could have been 4.5 million more people
and 1.4 million more jobs within the greenbelt

6. Method
Polycentricity Analysis
• Three-center polycentric models were modified by
adding two dummy variables to represent the
greenbelt and the non-greenbelt core
• Polycentric density function
• Three-center model (Seoul’s CBD, Kangnam, and
Incheon) works best
Results
Green Belt Scenario:
• On average, about 80 percent lower employment and
population densities in the greenbelt than in the core city.
Non- Green Belt Scenario:
• Employment densities within the greenbelt would have
tripled, while population densities would have more than
doubled
• Densities would be lower both in the core area inside the
inner-ring greenbelt boundary and beyond the greenbelt
• 45 percent decline in employment densities and a 55
percent decline in population densities at the core
Suggests that the major impact of the greenbelt
has been to aggravate core-city congestion than to stimulate
peripheral growth.
However, employment location has been
concentrated in the inner side of the greenbelt (causing
excess commuting for people who are jumping over the other
side of greenbelt for living

7. Results Summary
Commuting Distance Savings:
• 5% saving (a reduction from 7.14
to 6.79 km)
• Total excess commuting costs
associated with the current
greenbelt: $352.6 M/year
($64.20 per commuter)
including value of travel time

8. • Significant implications for urban land use and transportation policies
• Urban agglomeration – businesses would want to harness the benefits
and stay at the core
Greenbelts may provide three main categories of benefits:
• amenity value related to scenic beauty, recreational
opportunities, and bequest/heritage values
• fiscal savings due to increased efficiency in the provision of
public services and infrastructure associated with more
compact development, and perhaps most significantly;
• a wide range of ecosystem services such as air purification,
habitat and biodiversity protection, flood control, water
supply and quality, and many others.
Urban Containment Policies and the Protection of Natural Areas: The Case of Seoul's Greenbelt
(Bengston & Youn, 2006)
The critical question that the
article wanted to provoke:
whether the concept of
counterfactual planning has any
merit when compared with other
nontraditional planning
approaches
Counterfactual analysis enables
evaluators to attribute cause and
effect between interventions and
outcomes
(PreventionWeb, UNDRR, 2022)
Reflection
➢ What if there was no restriction in settlement generation at
Shivapuri Nagarjun National Park ?

9. Thank You