Mike McCoy

Information Center for the Environment

U.C. Davis

http://ice.ucdavis.edu

Modeling 101Fall - 2006

• Essentially 5 types of models

– “Delphi” Expert or Citizen Panel

– Trend Model

– Accessibility Forecasting

– Micro-Economic Land Use Models

– Rule Based Land Use Models

• Strengths and Weaknesses:

A Very Short Course in Modeling

Delphi Expert/Citizen

• Delphi Captures Professional Planning

and Real Estate Knowledge

• Delphi Records Community Preference

• Most Delphi Programs Are Graphically

Rich

PLACE3S

Method

Structured discussion

Sketch planning

Visual simulation

Economic feasibility estimation

Travel demand estimation

Energy consumption estimation

Preferred Scenario

DELPHI “Knowledge Base”

• Results Are Panel Dependant

• Makes “the zoning assumption”

– “If we zone it they will come”

Trend Forecasting

• Acknowledges Regional History

• Considers Past Trends

• Relates “Features” To Past And Future

Growth

Trend Forecasting

• The Future Is Not Fully Shaped By The

Past

• Constraints Have Not Been Well

Represented In These Models

Accessibility Forecasting

• Measures “Attraction” Of Housing Zones– Historic Growth, Vacancy, Trends

• Uses Jobs-Housing Balance– Employment In-Zone, Travel Time To Other Zones

• Considers Past Residential Trends– Same As “Trend” Model

• The Future Is Not Fully Shaped By The Past

• Accessibility Is Over-Represented Relative

To Other Economic Factors

Accessibility Forecasting

Micro-Economic Models

• Use “Real” Economic Chains

– Production location to exchange location; to consumption

location; for all goods, services, residences and labor

• Uses Real Market Mechanisms To Allocate

Commercial and Residential Space Development

• Measures Improvements In Consumer and

Producer Welfare

Economic Interactions:Production - Exchange - Consumption

totalconsumption

totalproduction

totalproduction

totalproduction

buying allocationprocess

commodityflows

exchangezone

exchangezone

exchangezone

selling allocationprocess

1

Economic Interactions:Production - Exchange - Consumption

totalconsumption

totalproduction

totalproduction

totalproduction

buying allocationprocess

commodityflows

exchangezone

exchangezone

exchangezone

selling allocationprocess

1

2

Economic Interactions:Production - Exchange - Consumption

totalconsumption

totalproduction

totalproduction

totalproduction

buying allocationprocess

commodityflows

exchangezone

exchangezone

exchangezone

selling allocationprocess

1

2

3

Micro-Economic Models

• Expensive And Time Consuming To Develop

• Shortage Of Trained Human Resources

Rule Based Models• Use Pseudo Economic Drivers

• Encourage User Input/Operation

• Can Represent Past Trends

UPlan 2.0 Simple “Rule Based Model”• Let’s users choose

– Everything• Future population (total or by special area)• General Plan Maps (current or speculative)• What attracts growth by land use type (roads, services…)• What discourages growth (endangered species, wetlands…)• Where growth absolutely can’t go (the river, the lake)

• Let’s users know– Where Development Goes

• Mapped by type, charted by amount by type – What Development Costs

• Transportation and Services Infrastructure• Environmental Infrastructure

Group and Add Weighted Grid Layers

4 0 0 04 04

4 24 22 2 2 2

0

Growth Attractions Group

Combined Effect

4 4 4 44 44

0 00 00 0 0 0

4

Urban Edge

0 4 0 00 04

4 00 00 4 0 0

00 3 0 00 30

0 00 00 0 0 0

3

Amenity Major Arterial

8 11 4 48 712

8 24 26 2 2 2

7

Ramp Proximity

Recommendations

• All– Use a Delphi Model like Places or a simple model like UPlan to

encourage vision creating participation.

• large MPOs (SCAG, MTC/ABAG, SANDAG, SACOG) – Use an integrated micro-economic model such as PECAS to test the

policies and investments you will need to achieve the vision

• Medium-sized MPOs and RTPAs – use simple urban models, such as UPlan, along with travel models to

test the policies and investments you will need to achieve the vision

• Share, Share, Share– Ideas, Experiences, Data

Two roads diverged in a yellow wood,

And sorry I could not travel both

And be one traveler, long I stood

And looked down one as far as I could

To where it bent in the undergrowth;        

Then took the other, as just as fair…

Choices

Model Development ProcessLand Use Models

Trip-Based Models Tour Activity

Standard Enhanced Complex Aggregate Simulation Aggregate Simulation

Stand Alone

Factored              

JudgementFresnoSan Joaquin 

   Boise New Hampshire

  

San Francisco County

Policy+Trends Allocation

 

SACOG Travel Model 1996

Edmonton

   

   

Conn-ected

Rule-Based Allocation

Merced Co.  UPlan

SACOG Travel Model + PLACES2003

  

   

   

Equilibrium Allocation (e.g. DRAM)

 San DiegoPuget Sound

AtlantaSantiagoPortland

   

   

Market-BasedAllocation

  

    

  Portland

Integ-rated

Aggregate Economic(Input/Output)

 SACOG MEPLAN2004

LondonSACOGPECAS2005

 

Oregon Statewide2004SACOGPECAS2006SANDAG PECAS2007

Disaggregate Economic Microsim-ulation

     

   

 

www.ice.ucdavis.edu/um

mcmccoy@ucdavis.edu