DEMOGRAPHY
ENVIRONMENTAL PLANNING
CAPABILITY BUILDING FOR
ARCHITECTS
Dates : April 24, 2013
Resource Speaker
Prof. Mike V. Guioguio,
g
, EnP,, REB
International School of Sustainable Tourism
Socio-Economic Sectoral Studies
(Analysis of the Situation)
formulating the goals and
objectives, targets
establishing development
thrust and spatial strategies
(
(spatial
ti l and
d sectorsl)
t
l)
Social Character
and Problems
Economic
Character and
Problems
land use proposals and
corresponding policies,
policies
programs and projects
implementing strategies
Infrastructure/
Utilities
monitoring/evaluation
strategies
Social,, Economic
and Environmental
Potential
DEMOGRAPHY
demography means description of the
people;
United Nations defines demography as the
scientific study of the human population
primarily with respect to size, structure
and development. It is therefore
concerned with the current size and
characteristics of human population
population, how
they were attained and how they are
changing
Population
as defined in the Glossary
y of Definition of
the National statistical Coordination Board
(NSCB) is the total number of individuals
in a territory at a specified time. It covers
both nationals and aliens; nativenative- and
foreign--born persons, internees, refugees
foreign
and other groups physically present within
the borders of a country at a specified
time. Thus, the total population of the
planning area ii.e.
e the city or municipality,
municipality
is the number of individuals physically
present at a specified time, that is the
census period.
period
Demographic Profile Used by
Pl
Planners
Population composition (age groupings
and sex ratios)
Population distribution (geographic pattern
of the location of people)
population
p
p
p
projections
j
((changes
g in
population brought about by its
components such as birth, death, and
migration relate
l
to the
h h
historicall and
d
projected growth of the population)
BASIC DATA REQUIREMENTS
OUTPUT/ANALYTICAL TABLES
Population Composition
1) Total Population By Age Group
and Sex
2) Age Dependency Ratio
3) Labor Force and Employment
(l t E
(later
Economic)
i )
4) SchoolSchool-Age Population (later
Social)
Total Population By Age Group and
S
Sex
ex
Age--Sex Structure plotted as population
Age
pyramid will show at a glance the
distribution of population in the locality.
The form of population pyramid, generally
reflects the pattern of fertility, mortality
and
d migration
i
ti
iin the
th past.
t Ab
broad
broadd-based
b
d
pyramid is brought about by very high
fertility while narrow
narrow--based pyramid
indicates low fertility/population growth
rate for some time.
S
di t ib ti
i best
b t expressed
d as sex ratio,
ti
Sex
distribution
is
i.e, a ratio higher than 100 indicates that there is
ap
predominance of male p
population
p
in the area
while less than 100 indicates a predominance of
female population. The sex ratio is lower in areas
where massive female in
in--migration is prevalent.
prevalent
Conversely, the sex ratio increases in areas
where out
out--migration is dominated by females.
Age--Sex Pyramids
Age
– The most important demographic characteristic
of a population is its age
age--sex structure;
– AgeAge-sex pyramids (also known as population
pyramids) graphically display this information
to improve understanding and ease
comparison;
– Age
Age--sex pyramids display the percentage or
actual amount of a population broken down by
gender and age. The fivefive-year age increments
on the
th yy-axis
i allow
ll
th
the pyramid
id to
t vividly
i idl
reflect long term trends in the birth and death
rates but also reflect shorter term babybabybooms, wars, and epidemics
Population Pyramid of the Philippines
POPULATION PYRAMIDS FOR 4 STAGES
OF THE DEMOGRAPHIC TRANSITION
MODEL
Age Dependency Ratio
Age provides the basis for estimating population
services/opportunities
/ pp
for different segments
g
of
population: school goinggoing-age, the dependent
population, the employable group and the
elderly,
y, as follows:
– 0-14 years old - child and youth, dependent population
– 1515-64 years old - productive population or working age
group
g
p
– below 15 and over 64 years old - dependent population
Age dependency ratio indicates the extent to
which those who are too young or too old to earn
a living depend for support on those who work,
computed as follows:
Population Distribution
SOME POPULATION
CHARACTERISTICS
Population density is a
measurement of population per unit
area or unit volume;
– The Crude Birth Rate (CBR) and Crude Death Rate
(CBR) are statistical values that can be utilized to
measure the growth or decline of a population; The
Crude Birth Rate and Crude Death Rate are both
measured
db
by th
the rate
t off births
bi th or deaths
d th respectively
ti l
among a population of 1000. The CBR and CDR are
determined by taking the total number of births or
deaths in a population and dividing both values by a
number to obtain the rate per 1000.
The Crude Birth Rate is called "crude" because it
does not take into account age or sex differences
among the population.
Crude Birth Rates of more than 30 per 1000 are
considered high and rates of less than 18 per 1000
are considered low.
Crude Death Rates of below ten are considered low
while Crude Death Rates above twenty per 1000 are
considered high.
Population Growth Rates
The rate of national growth is
expressed as a percentage for each
country, commonly between about 0.1%
and 3% annually;
– Natural growth represents the births and
deaths in a country's population and does not
take into account migration;
– The overall growth rate takes migration into
account;
– Population at t + 1 =
Populationt + Natural increaset + Net
migrationt
Doubling
g Time
– "Doubling Time,"
Time," tells us how long it will
take for a country's
country s current population to
double. This length of time is determined
by having the growth rate as the divisor of
70 in
i a division
di i i
formula.
f
l The
Th number
b 70
comes from the natural log of 2, which is
.70.
M
Measures
off Population
P
l ti
Change
Ch
Calculating Percent Change
Components
Co po e ts of
o Population
opu at o Growth
Go t
Population change can also be
expressed in terms of the
components of demographic change.
change
The components include:
Fertility
Mortality
Migration
Population Change
Annual
ua Rate
ate o
of Population
opu at o G
Growth
o t
Example
SHORT--CUT FORMULA
SHORT
Example
POPULATION PROJECTION
METHODS
TREND EXTRAPOLATION METHODS
Linear Equation
q
Extrapolating the Population into the Future
– The
Th Li
Linear Equation
E
ti
– Assumption:
–
The linear model assumes that population growth is
growing at absolute equal increments per year, decade,
or other unit of time. It also assumes that growth will
follow a similar pattern in future years.
– When best to use:
–
Use when the p
pattern of g
growth is similar to a
straight line. This tool is especially useful when
projecting areas experiencing slow growth.
Equation (Linear)
Guioguio, Mike V. Population
Use of Linear Regression Analysis in Linear Equation
EXPONENTIAL
The exponential curve displays a pattern of constant
constant, rapid
population growth. It is an arched upward curve that has
no upper limit.
Assumption:
– Population is assumed to grow at a geometric rate; i.e.,
with each unit of time, the absolute addition of
population continues to get larger and larger, as shown
g
6
6--4.
in Figure
When to Use
– This method is suitable for shortshort-term projections of 5
5-10 years for rapidly growing regions. Note that it can
produce unrealistically high projections over longer
periods of time.
Equation (Exponential)
Example: Project Population in 2012 for Las Piñas
Modified Exponential Model
Assumption
– Population growth reaches an upper limit in
the future,
future at line K.
K
When to Use this Model
– Use this model in locales that previously
experienced
d high
h h growth
h rates and
d are
currently experiencing growth at a slower
pace.
Modified Exponential Equation
An example of the modified exponential curve is provided below. The upper
limit for K is set at 8,000 residents. It is assumed that population growth is slow
as a result of declining economic opportunities in the locale
locale.
To accept this projection, it is necessary to study the economy of the area
as well as the carrying capacity of the land to determine if the estimate is
g It mayy also be necessaryy to studyy the components
p
of
too low or high.
demographic change - migration, fertility, and mortality. For rural districts, in
particular, out-migration can have a major impact on population size.
Extrapolation Summary
i important
i
t t to
t identify
id tif the
th projection
j ti
t l that
th t fits
fit the
th
It is
tool
available information and provides the most reasonable
projection of the future. It is a difficult task that requires
investigating various tools as well as the economic and
demographic
d
hi b
behavior
h i off the
th locale.
l
l
The following suggestions can aid in the selection and
application of appropriate tools.
Plot projection results on a graph and then determine if the
plot best fits the observed data.
Use a different method that fits the assumptions of the data
and perform another projection
projection. Do strong differences
exist? If so, determine why. Is it the data used or the tools
employed? Were there enough census takings? Was a good
start date selected for the first census period?
Check
Ch k th
the b
basic
i assumptions
ti
off each
h method
th d employed.
l
d Do
D
the data support the assumptions?
Examine the social, economic, and demographic trends that
are taking
gp
place. Will the trends continue in the future? Do
they support the projection?
Prorating Projection Tools
The ratio method projects population growth for a sub
sub-area using population projections for a larger or parent
population.
p
p
A regional
g
p
projection
j
can be used to p
project
j
the
population size of districts, and a projection for the country
can be used to project the population size of a region.
Assumption
– Local population change is highly dependent on what happens
to the population in the surrounding regions or states. The
ratio method can be used to project population growth for the
local area if two conditions are met: similar population
patterns exist for both the locale and the p
p
parent p
population;
p
;
and it is expected to continue in the future.
– The ratio method also assumes that a projection exists for the
larger or parent population. As indicated in Lesson 5,
projections for large areas such as a country, province, or
region
i
ttend
d tto b
be more reliable
li bl th
than those
th
produced
d
d for
f
smaller locales.
When to Use this Method
– Use this method for p
projecting
j
g the total p
population
p
size for 5 10+ year periods (barangay, ageage-groups).
The Ratio Method Summary Equation
Example
Supposing the only data on Las Pinas population is 2000
population of 427,780 and you are asked to project the 2012
population of Las Pinas?
First Step=Get the % share of 2000 population of Las Pinas to the
2000 population of NCR which is a parent area of Las Pinas and
have complete data on 2000 and 2007 census:
2nd Step= Project NCR’s population for 2012 using the various
extrapolation methods, in this case use the exponential method:
Example (cont.)
3rd Step=Multiply
Step Multiply results of Step 1 with the
results of Step 2:
How to Use this Tool
U historic
hi t i census data
d t to
t graph
h the
th subb-area population
l ti
Use
sub
and the parent or state population to see if similar growth
is taking place.
Collect projections for the parent population. Examine
differences in the projections and determine why the
differences exist. What methods were used and what were
the assumptions?
The ratio tool has a number of advantages over
extrapolation techniques. Computation is fast; it only takes
a few
f
minutes
i t once the
th data
d t and
d a reliable
li bl projection
j ti
are
available. Revisions are simple, and the ratio tool can be
used to make longlong-range projections. There are, however,
some disadvantages. First, like extrapolation tools, the ratio
t l does
tool
d
nott supportt the
th study
t d off changes
h
in
i births,
bi th
deaths, and migration. In addition, it requires a reliable
projection for the larger area. Finally, it is highly dependent
on the assumed relationship between the subsub-area and the
l
larger
or parentt population.
l ti
THE COHORT COMPONENT POPULATION PROJECTION METHOD
The cohort component technique uses the components of
demographic change to project population growth. The technique
projects the population by age groups,
groups in addition to other
demographic attributes such as sex and ethnicity. This projection
method is based on the components of demographic change
including births, deaths, and migration.
To project the total population size, and the number of males and
females by 5
5--year age groups, find the number of people who
survive or are expected to be alive in the future. Add to the
survived population number, the number of births that take place
and
d th
the number
b off nett migrants.
i
t
Assumption
– When the cohort component method is used as a projection
tool, it assumes the components of demographic change,
mortality, fertility, and migration, will remain constant
throughout the projection period. As a forecasting tool,
planners can alter the vital statistics and migration
p
g
estimates
to reflect their view of the future.
Strong Suggestion
– When making a 10
10--year projection, it is best to perform two
separate projections: a projection for the first 5 years and
then a projection for the next 5 years. The result of the first
projection is used to perform the second round of the
projection. In some cases, planners alter demographic rates to
reflect their vision of the future for a locale.
When to Use this Method
– Use the cohort component method when population
projections by age and sex are needed for 5 years, 10 years or
longer periods of time. This projection tool allows planners to
examine
i
the
h future
f
needs
d off different
diff
segments off the
h
population including the needs of children, women in their
reproductive years, persons in the labor force, and the elderly.
It also allows planners to project the total size of the
population The results can be used in all aspects of local and
population.
regional development plans.
Applying the Method
The goal is to project the number of women for the district from
years 20002000-2005.
S tti
Setting
up the
th Table
T bl
Discussion
The cohort component population projection method follows
the process of demographic change and is viewed as a
more reliable projection method than those that primarily
rely on census data or information that reflects population
change.
change It also provides the type of information needed to
plan for services to meet the future demands of different
segments of the population.
Like most projection tools
tools, there are disadvantages to using
the cohort component method. First, it is highly dependent
on reliable birth, death and migration data. Thus, it may be
difficult to collect the information to apply this tool. Second,
it assumes that survival and birth rates and estimates of
net migration will remain the same throughout the
projection period. In addition it does not consider the non
non-demographic factors that influence population growth or
decline.
decline
Even though problems exists, this projection method is the
most widely used tool by planners since it provides
information on the potential growth or decline of a locale by
age and sex.
STRUCTURAL MODELS
Often very complex in nature,
nature
models falling into this group explain
population growth (dependent
variable) through a variety of nonnondemographic (independent) variables
such as employment, wage levels,
and local amenities as well as land
use and transportation models.
Pop = f (income,
(income employment,
employment taxes,
taxes
investments)
END OF DISCUSSION!!
Bibliography:
– http://www.cpc.unc.edu/measure/training/me
ntor/population--research/pap
ntor/population
research/pap))
– Department of the Interior and Local
Government (2005). Rationalized local
planning system of the Philippines
Philippines. Quezon
City, Philippines: Author;
– Housing and Land Use Regulatory Board
(2007). CLUP guidebook volume 2: A guide to
sectoral studies in the CLUP preparation.
Makati City, Philippines: Author