Influencing policy (training slides from Fast Track Impact)
Agent based simulation of GENTRIFICATION
1. Gentrification
● Production side ● Consumption side
explanations explanations
– Rent-gap theory (N.Smith, – Post-industrial shift
1979) G. depends on the ● Predominance of white collar
movement of capital from one work
area of the city to the other in
pursuit of higher profit
● 'Creative' classes
Urban development, technological shift,
● Fashion effects (NY 'loft
depreciation create localized mismatch living')
between current and potential land use
2. This model
● So far...
– Implements the rent-gap theory
● Wishes to
– Couple economic and cultural/diversity dynamics.
● Gentrification affects the cultural other than economical
identity of places.
– Embed + compare production and consumption
factors → “theoretical synthesis”
– Predict the future! :-)
3. Agent model
➔ Income level [0-1] (random)
➔ Mobility propensity (Poisson distribution 0.06/year)
➔ String culture (n=10) |_|_|_|_|_|_|_|_|_|_|
0100101011 1011011001
0
1
0
0
0
0
1
0
1
0
● Long-time neighbours interact → Cultures mix
● Interaction more likely when common traits exist
4. City model
● Individual dwelling
– Condition [0-1] random
– Price [0-1] = cond + 0.15
● Neighbourhood
– Allure (sticky and approximate)
|_|_|_|_|_|_|_|_|_|_|
Price-gap:
difference between a property's price and
mean price of surrounding properties
5. Parameters
● Kapital level
– Number of properties receiving investment each
year
● Decay factor
– Constant monthly decay. Set at 0.0015
● Immigration rate
– Set at 3% per year
6. Economic processes
● Decay
– Constant decay (0.0015/step)
– Empty properties decay 1.5x faster
– Price is lowered as consequence of decay and if
empty for 6 consecutive months
● Investment
– K properties with wider price-gap receive investment
● Price = mean neighbour's price + 15%
● Condition = 0.95
12. K=25
Population dynamics
Neighbourhoods
steadily increasing
the mean income,
while the population
decreases and
increases in waves,
signal gentrification +
displacement: the
poor go, the rich
Gini = 40; move in.
Slum = 30%
13. K=25
Cultural dynamics
➔ Cultural uniformity is
maximized in areas where
prices have been stable for a
long time at a high level
➔ Little clustering happens in
poor areas: the "slum" is a
transition zone for poor
immigrants, who quickly enter
and leave.
14. Population dynamics
K=35
➔ Higher capital = higher prices = lower population
➔ Cycles of investment and disinvestment
➔ Rat race around the city
➔ Reminds of Smith's definition
15. Cultural dynamics
Culture uniforms when
prices are steady for
some time, allowing for
➔ residents to stay put
➔ cultures mix
➔ self-selection of in-
movers via “allure”
16. Future
● More realistic residential mobility
● More heterogeneous agents
– Classes of agents: “gentrifiers” and “non-
gentrifiers”
● Population dynamics
● Actual city land values
Notas do Editor
Gentrification: Inflow of affluent residents in working class areas. This results in displacement of the original population and in the change of the looks of the area (different shops, art galleries, etc.) Gentrification is an outcome of investments shifting from one area to another in pursuit of profit. BEFORE THE MOVEMENT OF PEOPLE THERE'S THE MOVEMENT OF INVESTMENTS. Investment happens in areas where the gap between the potential and the actual land/property value is wider