GIS for Retail Analysis: Buffer and Overlay Flashcards
What is GIS for retail analysis?
Use of buffer and overlays in order to create catchments around store locations to identify expected levels of demand
How did Pearson (2007) use GIS to map demand?
Population overlay
Identified 6 variables important for unique demand estimation
Households must satisfy all 6 variables in a ‘sieving effect’ leaving only households that match criteria
What were the 6 variables used by Pearson (2007)?
- Household income > $45,000
- Family income > $60,000
- Bachelor’s degree or higher > 40%
- Median age between 25 and 46
- Median mortgage > $1,050
- House value > $139,000
Multicollinearity between variables
What is sieve mapping?
Creation of variables that need to be satisfied to leave very few, but ideal, store locations - achieved through the creation of buffers around existing stores drawn in relation to store size
Can remove locations not right for store e.g. low income areas for Waitrose
Can overlay a number of characteristics to get the most accurate idea location
How was GIS used for mapping demand for the Pawn Brokers in Houston?
Sieve mapping through a scoring system
Created 5 categories
Each category split into ranges and awarded points 1-5
Variables 1, 2, 4 and 5: low values = 1, high values = 5
Other way around for variables 3
Higher the total score, better the locations
Mapped through hotspot mapping
What were the 5 categories used in the Pawn Brokers example?
- pop. size
- household income
- no. rented households
- household size
- pop. density
What are the 3 ways GIS can be used for network analysis?
- Accessibility
- Location-allocation models
- Food miles analysis
GIS for network analysis: ACCESSIBILITY
Used to assess how well provided/easy it is for customers to access e.g. food deserts
GIS for network analysis: LOCATION-ALLOCATION MODELS
Used in network analysis in order to find the ideal location for existing demand and travel time for consumers
- Take a map of demand variables and ask where the best ‘x’ no. locations would be
- Model tries ‘x’ locations in every possible combination
- Calculates distance people would travel to access tore
- Finds idea location to min. travel time
How does ArcGIS map location-allocation models?
Creates ‘spider maps’
Centre of spider is suggested location
‘Legs’ = distance travelled
Why are location-allocation models limited?
- Assumes only travel from home
- Assumes brand loyalty
- Assumes everyone has a car
What is the Hotelling Theorm (1929)?
Argues against the use of LAMs as says that optimum location based on distance is incorrect because of the need for competition:
- Retailers will move/locate near competitors to steal customers
- Market is too competitive to serve optimal consumer base profit driven
What 4 reasons have lead to an increase in food miles?
- Agricultural trade liberalisation
- Technological innovation & agricultural intensification
- Changing consumer demands
- Logistical changes in domestic food supply chain
How has agricultural trade liberalisation increased food miles?
Agreement on Agriculture, 1995
Meant that domestic support was cut and export subsidies reduced - lead to an increase in access to foreign products which are often cheaper
How has tech. innovation and agricultural intensification increased food miles?
Increased mechanisation leads to more produce
Increased specialisation and efficiency
Lead to surplus of produce that needs to be distributed elsewhere, therefore abroad