Microsimulation in Canada: Lessons from Statistics Canada Chantal Hicks British Society for Population Studies University of Sussex, September 11, 2009

Microsimulation in Canada: Lessons from Statistics

Canada

Chantal Hicks

British Society for Population Studies

University of Sussex, September 11, 2009

September 11, 2009Statistics Canada • Statistique Canada2

Note

Opinions represented in this paper represents my views and are not the views of Statistics Canada

More emphasis on the models with which I’ve been involved

Microsimulation in the Government of Canada


Microsimulation in the rest of Government of Canada

Human Resources and Skills Development Canada• Static tax/transfer model

(SIMTAB) • Dynamic pension model

(DYNACAN). Funding ended June 2009

• Employment Insurance model

Department of Finance• Static tax/transfer model

(TTSIM)• Corporate tax model

Health Canada and Public Health Agency of Canada• Pharmacare model• Human resource models• First Nation model• Pandemic Flu model


Overlap exists

At least 3 models which calculate taxes and transfers starting from the same public use survey (Survey of Labour and Income Dynamics)


Modeling at Statistics Canada Done by Four Groups

Modeling Division• Modelling technologies• Socio-economic models• Infectious disease models

Health Analysis Division• Health and disease models

Demography Division• Demographic projection

models

Human Resources Development Division• Personnel models


POHEM(Modgen)

Major* Microsimulation events at Statistics Canada

1984 1988 1992 1996 2000 2004 2008

SPSD/Mconceived

MichaelWolfsonArrives

DEMOSIM

POHEM(APL)

FADEP

SPSD/MPublic release

CaremodLifePaths HIVMM

CVMM

IDMM

XECON

PopModM

RiskPathsModgen

PERSIM


Social Policy Simulation Database and Model (SPSD/M)

First model developed at Statistics Canada Static tax/transfer model Synthetic database which combines survey and

administrative data Model written in C Visual Basic front end released in 2006



1984 1988 1992 1996 2000 2004 2008

SPSD/Mconceived



Visual SPSM


FADEP (Family and Demographic Projections)

Part of CEPHID (Canada‘s Elderly Population: Health, Income & Demography)• Hybrid Static & Dynamic models

Dynamic model of projection of family structure Closed population Written in C++



1984 1988 1992 1996 2000 2004 2008

SPSD/Mconceived


FADEP



POHEM (Population Health Model)

Longitudinal model of health and disease Cohort model Comparison of competing health interventions Multiple versions

• Some use synthetic data and some microdata

First version written in APL



1984 1988 1992 1996 2000 2004 2008

SPSD/Mconceived


POHEM(APL)

FADEP



Lessons Learned by 1993

Dynamic models were hard to maintain and to modify Coding of models was time consuming and error prone Flexible/modular design essential Writing to disk during simulations slows speed

significantly Closed dynamic models make high demands on

memory and/or have significant sampling variability


Modgen Generic tool to create dynamic microsimulation models C++ compiler pre-processor Features

• Event queue• GUI • Derived states• Tables and microdata output (tabulation is on-the-fly)• Continuous or discrete time• Calculating Monte Carlo variability• Multilingual cross-referenced documentation


POHEM(Modgen)


1984 1988 1992 1996 2000 2004 2008

SPSD/Mconceived


POHEM(APL)

FADEP


Modgen


LifePaths

Dynamic model of individuals and families designed to analyse government programs

Overlapping cohort model Full cross-sectional population by 1972 Some of the main research areas: student loans,

pension policy, time allocation, intergenerational issues

Written in Modgen


POHEM(Modgen)


1984 1988 1992 1996 2000 2004 2008

SPSD/Mconceived


POHEM(APL)

FADEP


LifePaths

Modgen


DEMOSIM (aka PopSIm)

Demographic projection model Projects population by visible minority status Starts by reading in the entire 2006 census (20%

of Canada’s population) Written in Modgen


POHEM(Modgen)


1984 1988 1992 1996 2000 2004 2008

SPSD/Mconceived


DEMOSIM

POHEM(APL)

FADEP


LifePaths

Modgen


CAREMOD

New model focusing on cost-effectiveness of cancer treatments and prevention

Based on POHEM Very short turnaround time – contract from

Canadian Partnership Against Cancer Part of contract is to put model on the web

• Generic technology being built which can be used for all Modgen models


POHEM(Modgen)


1984 1988 1992 1996 2000 2004 2008

SPSD/Mconceived


DEMOSIM

POHEM(APL)

FADEP


CaremodLifePaths

Modgen


PERSIM

Model designed to look at personnel needs for government departments

Written in Visual Basic Prototype in Modgen created in 2008 Funding sought to migrate it to Modgen


POHEM(Modgen)


1984 1988 1992 1996 2000 2004 2008

SPSD/Mconceived


DEMOSIM

POHEM(APL)

FADEP


CaremodLifePaths

PERSIM Modgen prototype

Modgen

PERSIM


POHEM(Modgen)


1984 1988 1992 1996 2000 2004 2008

SPSD/Mconceived


DEMOSIM

POHEM(APL)

FADEP


CaremodLifePaths HIVMM

CVMM

IDMM

XECON

PopModM

RiskPathsModgen

PERSIM

Key Issues


Funding

Different projects have used different funding mechanisms at different times

Core funding is available at Statistics Canada


Main sources of funding

Core Funding Contracts Sales to clients

SPSD/M X X

POHEM X X

LifePaths X X

DEMOSIM X

PERSIM X X

Modgen X X

Much development included in

other projects

Pohem funded creation

WHO project funded

improvements to interacting

population

CAREMOD funding

web interface

HRSD major source of funding

GAPS has provided funding in recent years – ending in

2010

Core funding critical – clients

unable to pay full cost


Who uses the models

Some models solely used by Statistics Canada for research at Statistics Canada

Others are used by the public Most models are run by Statistics Canada for

projects funded by external users


Public availability

Released to public

Not yet released

SPSD/M X

POHEM X*

LifePaths X*

DEMOSIM X*

PERSIM X

Modgen X

CAREMOD will be publicly available Plan to

have public version of DEMOSIM in 2010 – data may

still be confidential

Personnel data

confidential

Only selected outputs


Major users

External users

Statistics Canada in partnership with clients

Statistics Canada

SPSD/M X X X

POHEM X X

LifePaths X X X

DEMOSIM X X

PERSIM X X

Modgen X X X

Only model where

external users represent majority

Few external users

Policy analysis

not in mandate

Number of external

users increasing


Staffing

Different groups have used different mix of personnel throughout the years

Use of single resource to do the programming has been a key difference


Staff mix

One person programs the model

Multiple people program the model

SPSD/M X

POHEM X X

LifePaths X

DEMOSIM X X

10 Lessons gleamed from 25 years of experience


Lesson 1: Have strong leadership

Michael Wolfson led microsimulation at Statistics Canada

Steve Gribble designed SPSD/M and Modgen Geoff Rowe spearheaded research and equation

estimation All were there from the start in 1984 = 25 years


Lesson 2: Hire and keep the best team

Takes time to learn microsimulation, best if personnel can stay for numerous years

Easier to do if team is big enough to allow for the possibility of working on new projects

Multiple projects using the same technologies makes this much easier to do

Modgen means that analysts as opposed to programmers can develop and maintain the models


Lesson 3: Invest in technology

Modgen led to rapid development of new models Fast creation of prototypes one of the methods

used to develop new markets Common language means a more flexible team Programming the model should take less time

that analyzing the data that goes into the model


Lesson 4: If it ain’t broke, don’t fix it

SPSD/M predates Modgen Written in C and has had no major overhaul in

>20 years Survived:

• Changes in operating systems• Frequent updates (~2x year)• External users from across the country

Visual interface was created 2006


Lesson 5: Survive through lean times

Policy needs ebb and flow Core funding important Diverse client base can cushion the blow Loyal clients can save the day


Lesson 6: Use “Strategic Opportunism”*

Technologies like MODGEN makes rapid prototyping simple • data analysis takes the time

Complex models take time to build Building on existing models makes sense

• CareMod built on POHEM• LifePaths used to study pension reform

* copyright Steve Gribble


Lesson 7: Complexity has a cost

Complex models, like LifePaths, are hard to keep up to date and have a large overhead

Can be hard to understand what is causing change

Hard to attract users


Lesson 8: Simplicity not always the answer

Simple models may not be able to answer the policy questions of the day

SPSD/M and Employment Insurance• SPSD/M has a certain amount of Employment

Insurance history built into it• Designed at a time when the policy question was

contraction• Current policy questions have to do with expansion:

model cannot answer these questions


Lesson 9: Links to clients and external groups essential

POHEM and SPSD/M, PERSIM and DEMOSIM team have strong links to external clients• Some important gaps remain

LifePaths has struggled on and off through the years to find significant external interest

Ties with the microsimulation community of Ottawa haven’t always been strong• New seminar series is trying to build a community• Try to keep people working in microsimulation

modeling


Lesson 10: Pick good names

Social Policy Simulation Database and Model (SPSD/M)

Or in French Base de données et modèle de simulation de

politiques sociales (BD/MSPS)

Thank you!

[email protected]

Documents

Microsimulation in Canada: Lessons from Statistics Canada Chantal Hicks British Society for Population Studies University of Sussex, September 11, 2009