International Workshop
on
Subnational Population Projections
using Census Data
17 – 18 January 2013
Beijing, China
Session 4:
Preparing subnational projections
using a bottom-up approach
• National projections with subnational
components: an integrated approach
• Stand-alone subnational projections using the
cohort-component method
National projections with
subnational components: an
integrated approach
Overview
National projections with subnational
components
• A national projection with subnational
components is usually performed by a central
authority of the country, often in collaboration
with regional or subnational institutions. One
approach could be the simultaneous preparation
of all subnational projections using the standard
cohort-component method and software. In a
second step, the national projection is then
obtained by aggregating all subnational
projections. For the latter, the projection
software needs to have special functionality.
Using Spectrum to generate
subnational projections I
• Spectrum offers a special functionality to
aggregate several projections into one for a
larger area (country)
• Spectrum does not (yet) provide consistency
mechanisms that guarantee that individual
projections are consistent with and add up to
the national total.
Using Spectrum to generate
subnational projections II
• Steps involved are:
• Prepare independently projections for each
subnational entity (region, province) and save
it. Include AIDS required.
• In order to aggregate the individual
subnational projections, create a list of
member regions and save it.
• Process the list.
• Obtain the summary indicators.
Using Spectrum to generate
subnational projections III
Using Spectrum to generate
subnational projections IV
Using Spectrum to generate
subnational projections V
Using Spectrum to generate
subnational projections VI
Using Spectrum to generate
subnational projections VII
Using Spectrum to generate
subnational projections VIII
Using Spectrum to generate
subnational projections IX
Using Spectrum to generate
subnational projections X
Using Spectrum to generate
subnational projections XI
• Spectrum can be used for explorative subnational
projections that can be compared and
aggregated.
• Spectrum lacks some features that are required
for a fully specified and consistent subnational
projection program, such as an ability to enforce
consistency with a given national projection and
complete output by age )some indicators.
• The necessity to specify HIV/AIDS adds
complexity.
National projections with subnational
components: Multistate approach
• Another, more comprehensive and elegant,
approach is to employ a multi-state or multiregional projection framework. Here the
subnational populations and their demographic
characteristics enter the model together.
National projections with subnational
components: Multistate approach
• The model has special – and demanding –
requirements regarding (internal) migration. For
each subnational area, migration needs to be
fully specified in terms of immigration by sending
subnational area and for emigration by
destination area. Altogether, this forms a gross
migration matrix with as many rows and columns
as there are subnational regions. If international
migration needs to be included, an additional
virtual region could be added representing the
outside world.
Stand-alone subnational projections
using the cohort-component
method
Overview
Stand-alone subnational projections
• There is a need for standalone population
projections that benefit for the advantages of
the cohort-component methodology but avoid
the heavy administrative and organizational
overhead of coordinated national population
projections with subnational components.
• Such need arises from emerging and ad-hoc
policy and planning requirements that need
population projection data as its basis.
Stand-alone subnational projections
• Standalone population projections can be
prepared like a national population projection,
using the same software.
• Migration needs to be dealt with in a more
comprehensive way, by combining internal
migration and international migration.
Stand-alone subnational projections:
Migration
• It is useful to prepare internal and
international migration separately, but to
combine both into net migration. As for
national projections, it is advisable to
formulate migration assumption in term of
absolute numbers.
Other software
• RUPEX US Census Bureau Rural-Urban
Projection Program with EXCEL interface
• United Nations MORTPAK projection program
PROJCT
• LIPRO multi-state projection program
(LIfestyle PROjections)
USCB RUPEX
Description
The program uses the cohort component method for projecting the
population by age and sex.
The projection is made following cohorts by single years of age, even if all
or some of the input data are in five year age groups.
Using interpolated values of central death rates from life tables, RUP
estimates the number of deaths and subtracts them from each cohort.
It also takes into account internal and international migration. Every year
births are estimated using fertility rates and the female population in
reproductive ages. The annual number of births constitute new population
cohorts that are followed through in the future.
USCB RUPEX
– Advantages:
• Reliable and well tested methodology
• Large user base
• Professional support
• On-site Training available
• Integration with analysis tools
– Disadvantages
• User interface somewhat non-intuitive (Excel based)
• Data format of input file text based and not self
explanatory
• Still in testing for Windows Vista/Win7
United Nations
MORTPAK Population Projection
LIPRO
• Multistate projection program developed by
NIDI, Netherlands
• Although originally developed for household
projections, the LIPRO computer program can
be used for a wide range of calculations in
multistate demography. LIPRO has been
extensively used for various applications, in
the Netherlands as well as in many other
countries.
LIPRO
• Consistency algorithms exist and can be
expanded.
• Powerful, but demanding.
• No further development
• Runs only under Windows XP
LIPRO
LIPRO
• Projection data must be prepared outside:
age-specific rates of change for each
region/unit. Their evolution over time can be
controlled through a scenario module.
Alternatively, the number of events by age
and sex can be inputted; LIPRO will then
calculate the rates/probabilities.
Challenge: Age-specific migration rate matrix:
Origin and destination, by age.
LIPRO
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•
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•
•
Belgium - LIPRO household typology
China - population projections Shanghai
Marital status projections for England & Wales.
Spain - population projections Catalonia
Paper on: Internal migration scenarios and
regional population projections for the European
Union. International Journal of Population
Geography
• http://www.nidi.knaw.nl/Pages/NID/24/841.bGFuZz1VSw.html
PADIS-INT
PADIS-INT
New features and advantages
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3.
4.
5.
Web-accessibility
Less environmental dependence: PADIS-INT does not rely on any
operating system (Windows, Unix, and Linux) and can be accessed
by any browser
Use of the latest technology, which enrich users’ interactive
experience and improve the robustness, efficiency, safety, and
reliability of the system and its distributed deployment.
Simple data input and flexibility: Users only need to provide very
basic data such as the age-sex distribution of the population in the
starting year and other demographic variables in the future such
as total fertility rate, age-pattern of fertility, life expectancy at
birth by sex, net migration rate by sex, and age pattern of
migration by sex.
Rich in graphics and outputs