Lesson 3: Creating a Demographic Profile

Course Objective 

Develop skills using simple demographic tools to guide planning decisions

Expected Outcome

Acquire skills to design a demographic profile examining past and present population characteristics for a given locale. The profile will aid in the understanding of changes in the total population, as well as changes in the composition of the population over time. The information may assist in the provision of services to different segments of the population such as children, elderly, and the working age population.

Three types of tools will be introduced in Lesson 3:

  1. Techniques to measure changes in the total population
  2. Methods to assess changes in the composition of the population
  3. Graphic ways to present the age and sex distribution of the population

3.1 Measures of Population Change

A simple way of measuring population change is to examine changes in the total population from one time period to the next. Equation 3-1 shows the calculation for population changes over time

Equation 3-1: Population Change Over Time

A

The calculation for percent change between two time periods is shown in Equation 3-2. Using data from Table 3-1, the following example demonstrates the use of Equation 3-2.

Equation 3-2: Calculating Percent Change, with Examples

B

Presenting the Information

To present population information, it is necessary to compare the data with another source of information. Selection of the second set of information is based on the geographic location of the area under study. For example, a comparison of the region of interest with other regions, and/or with the entire country, may be preferred. For district plans, population change can be compared with other districts, or with the region in which the district is located. A comparison allows the planner to understand if his/her region or district is growing slower or faster than another locale. Table 3-1 provides information on changes in the total size of the population over time for both the Greater Accra region and the entire country. The information may be used to determine if the total population size of the Greater Accra region is growing slower or faster than the entire country.

Table 3-1
Percent Change in the Greater Accra Region and Ghana
 
Time Period Population of Greater
Accra Region
Percent Change Population of
Ghana
Percent Change
2000
1984
1979
1960
2,909,643
1,431,100
851,614
541,933
---
103.31
68.04
57.14
18,412,247
12,296,081
8,559,313
6,728,815
---
49.74
43.65
27.20

Source: Population Censuses of Ghana, 1960, 1970, 1984 and 2000

What Additional Information is Needed?

Further analysis is needed to identify why growth is taking place. It is also necessary to identify which segments of the population are experiencing growth. Information on the location(s) where growth is occurring is also needed.

Information on economic activities is needed to understand why growth is taking place. Once these data are collected, planners must determine if the current economic trends will continue in the future. If economic growth is expected to continue, you may assume that population growth will also continue.

Planners also need to know among which segments of the population growth is taking place. For example,

  • Is population increasing among particular age groups?
  • Increasing among men?
  • Increasing among those engaged in trade versus those involved in manufacturing jobs?

Percent change can be calculated among age groups to determine where growth is occurring. It is possible that new immigrants, with young children, are moving into the region. Growth of families with young children has implications for services and infrastructure including education, jobs, health care, and transportation needs. Such information is needed to determine the need for new services and the expansion of existing services and infrastructure such as roads, water and electricity.

Planners must also identify locations within a region where growth is taking place to determine the best location for new services and facilities:

  • Is growth occurring in eastern districts of the region?
  • Occurring in urban areas?
  • Occurring in rural areas?

Information on the census boundaries for each census taking is also needed. Changes in census boundaries can account for increases in population.

Population Density

Planners are interested in changes in population density, that is, the number of people occupying a given area or unit of land.

Equation 3-3: Population Density

C

In rural areas, where a high percentage of the population is engaged in farming activities, the population density tool allows planners to calculate the number of people that reside and/or work on a unit of land. In urban areas, it can be used as a measure of crowding. The land area is usually expressed as population per square miles or kilometers. Density measures can be applied to two census periods to observe changes overtime. The information can also be transferred to a map to observe geographic changes.

Table 3-2 includes land area, total population, and calculated land densities for different regions of Ghana for the years 1984 and 2000.

 
Table 3-2
Density of Population by Region, 1984 and 2000, Republic of Ghana
 
  1984 Census 2000 Census
Regions Area in
Square Kilometers
Population Density Population Density
All Regions
Western
Central
Gt. Accra
Volta
Eastern
Ashanti
Brong Ahafo
Northern
Upper Eastern
Upper Western
238,533
23,921
9,826
3,245
20,570
19,323
24,389
39,557
70,384
8,842
18,476
12,296,081
1,157,807
1,142,335
1,431,099
1,211,907
1,680,890
2,090,100
1,206,608
1,164,583
772,744
438,008
52
48
116
441
59
87
86
31
17
87
24
18,412,247
1,842,878
1,580,047
2,909,643
1,612,299
2,108,852
3,187,601
1,824,822
1,854,994
917,251
573,860
77
77
161
897
78
109
131
46
26
104
31
Source: Ghana Statistical Service (August 2000)
2000 Population and Housing Census,
Provisional Results

Population density has increased in all regions of Ghana for this period. Accra, located in the Greater Accra region, experienced the largest increase. Changes in population density for this region could imply possible crowding in the city. Further analysis can be performed by calculating density rates for districts within the greater Accra region.

Components of Population Growth

Population change can also be expressed in terms of the components of demographic change. The components include:

  • Fertility
  • Mortality
  • Migration

Equation 3-4 allows planners to observe which components of demographic change are contributing to the growth or decline of a locale.

Equation 3-4 Population Change

D

Planners are also interested in how fast a locale is growing each year. This information allows them to adjust plans to meet current and future needs of services that the population uses such as water, electricity, and garbage collection. The annual rate of population growth can be calculated using Equation 3-5.

Equation 3-5
Annual Rate of Population Growth

E

The calculations used in Equation 3-5, are based on the exponential rate of growth, which follows the principle of compound interest. That is, the population is assumed to experience a constant rate of growth, repeated or maintained year after year, which produces larger and larger increments simply because the total population steadily becomes larger. Demographers use base 10 logarithms and the natural logarithm e in calculations of the annual rate of population growth. An example of the use of Equation 3-5 is shown below using 1984 and 2000 census data of the Greater Accra region (Table 3-1).

  • 1984 Census = 1,431,100
  • 2000 Census = 2,909,643

Example of Equation 3-5
The Greater Accra growth rate

F

Alternative example of the Annual Rate of Population Growth Equation

Use the following alternative to the annual rate of population growth equation (Equation 3-5) when a spreadsheet program, or calculator with log functions is not available. This method is easy to use, but the result is not as accurate as the one in Equation 3-5.

G

In planning, it is necessary to know how long it would take for a region, district, or city to double in population size. The Population Reference Bureau (PRB), based in the United States, provides a simple method to estimate doubling time. This equation is very useful for calculating the growth of rapidly growing areas such as large cities. Equation 3-7, developed by the PRB, is applied below to the annual rate of growth of the Greater Accra Region.

Equation 3-6: Doubling Time for Greater Accra Region

H

Results: It will take 15.8 years for the Greater Accra Region to double in population size. The region will grow as a result of in-migration and natural increase, that is births minus deaths.

Uses for this Information

Should services and the infrastructure be increased to meet the demands of new residents, in particular to the capital city of Accra? Or, should strategies and plans be developed to make rural areas and other urban areas more attractive to potential migrants? The Ghanian government's regional and national development plans should be used to determine strategies to deal with this expected increase in population. To fully understand the changes in the population, each component of population growth must be investigated separately. Planners must answer the following questions.

  • Is growth due to high birth rates in the region?
  • Is migration primarily responsible for increases or declines in the population?

Demographers use rates and ratios to examine the separate components of demographic change, as well as changes in the composition of the population. For example, an examination of the birth rate, overtime, provides insights into the contribution of fertility to population growth. Another example is the use of migration rates. Migration rates provide information on the impact of migration on population growth.

3.2 Ratios and Rates

Ratios measure the size of the first population group A in terms of another population group B.

I

This ratio is read as the number of units of A per 100 units of B. Demographers, in general, state ratios in terms ofper 100 or per 1,000 people. Several types of ratios will be discussed including:

  • Sex ratio
  • Aged-Child ratio
  • Age dependency ratio
  • Child-Woman ratio

Sex Ratio

The sex ratio, shown in Equation 3-7, summarizes the sex composition of a given population - the number of males per 100 females within the same population of a given locale.

Equation 3-7
Sex Ratio

J

Sex ratios can be calculated for an entire country, region, or district.

Note:

  1. If the ratio = 100, there is a perfect balance between the sexes.
  2. If the ratio is < 100, there are more females than males.
  3. If the ratio is > 100, there are more males than females.
     

Why Use the Sex Ratio?

It is extremely difficult to record migration (population movements in and out of locales). Sex ratios, however, can be used to get insights on population movement. If the sex ratio is constructed by 5-year age groups, it crudely indicates in- or out-migration among age groups.

In later years, the sex ratio crudely indicates mortality. In general, there are more males than females in the earlier years as there are typically more male births than female births. In rural areas, there tend to be more females, especially for communities that experience out-migration of men to urban areas. In cities with heavy in-migration, there tend to be more men than women who are in the working age groups. In later years, after age 55, there are usually more women than men as a result of higher deaths among men in their later years of life.

Equation 3-7
Example Calculating the Sex Ratio for Ghana

K

There are 96.14 males per 100 females in Ghana.

Table 3-3 shows sex ratios calculated by age groups for Ghana's Volta region.

 
Table 3-3
Sex Ratio for the Volta Region of Ghana, 1984
 
Age groups
 
ales
 
Females
 
Sex Ratio
 
0-4
5-9
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85+
96,052
96,807
78,864
67,713
47,232
37,303
29,672
23,290
19,551
19,635
17,193
11,535
11,440
8,524
7,861
4,772
4,187
5,309
96,409
94,659
72,404
60,663
53,767
45,356
36,543
8,186
24,877
23,568
21,199
14,217
15,465
10,727
9,261
5,604
5,229
6,833
99.62
102.26
108.92
109.81
87.84
82.24
81.19
82.62
78.59
83.31
81.10
81.13
73.97
79.46
84.88
85.15
80.07
77.69
Source: Statistical Service (1984)
1984 Population Census of Ghana,
Demographic and Economic Characteristics of Volta Region,
Accra: Republic of Ghana.
 

Sex ratios from Table 3-3 indicate there are more males than females in the 5-19, 10-14, and 15-19 age groups. From ages 20-85, there are more females than males in the region. It is possible that men aged 20-59 have left the region for economic opportunities. The differences beyond age 60 can be due to both mortality and migration. The analysis has implications for the supply of labor in the region. In addition, it indicates that more women reside in the region than men, in the working age groups.

Aged-Child Ratio

The aged-child ratio indicates whether or not a population is young or aging. Use this ratio if planning services for these two groups in the community.

Equation 3-8
Aged-Child Ratio

L

An example of the aged-child ratio for Ghana in 1984 is shown below.

Example of Equation 3-8
Aged-Child Ratio for 1984

M

In this example there are 8.91 elderly residents per 100 children in Ghana in 1984.

For a quick exercise, calculate this ratio for two census periods to determine if a trend is taking place. This ratio, for example, is compared with that of the census data of 1970 in Ghana.

Another Example of Equation 3-8
Aged-Child Ratio for 1970

N

This example indicates there are 7.75 elderly per 100 children in 1970.

What do these ratios suggest?

There is slight increase in the number of elderly in Ghana between the two census periods, 1984 and 1970. More services may be needed to meet the needs of a segment of the population that will have different health, housing and transportation needs than children.

Age Dependency Ratio

The age dependency ratio indicates the number of people who are viewed as being dependent versus those that are viewed to be in the "working age groups."

Equation 3-9
Age Dependency Ratio

O

The following examples use 1970 and 1984 census data taken for Ghana.

Example of Equation 3-9
Age Dependency Ratio for Ghana 1984

P

There were 96.18 dependents per 100 working age population in Ghana in 1984.

Another Example of Equation 3-9
Age Dependency Ratio for Ghana 1970

Q

In 1970, there were 133.9 dependents per 100 working age population in Ghana.

What Does the Data Imply?

In Ghana, the age dependency ratio has decreased over the period from 1970 to 1984. In 1984, however, the country was supporting a large dependent population, mostly children who required educational and health facilities. The 2000 census data can be used to see if the dependency ratio continues to decline. In addition, it can be compared with the aged-child ratio to see if children continue to be the primary dependent population.

Child-Woman Ratio

The child-woman ratio crudely indicates fertility levels in an area and is used in areas where fertility data are not available. It is used to measure the incidence of childbearing among women in their reproductive years. It only provides information, however, on those children ages 0-4 who have survived. The advantage of this tool is that it can be calculated using only census or survey data.

The calculation for the child-woman ratio as shown in Equation 3-10.

Equation 3-10
Child-Woman Ratio

R

The following examples use 1970 and 1984 census data for Ghana.

Example of Equation 3-10: Child-Woman Ratio for Ghana, 1970

S

Another Example of Equation 3-10: Child-Woman Ratio for Ghana, 1984

T

The child-woman ratio for the two census periods show that the ratio of children ages 0-4 to women in their reproductive years is declining. This result roughly suggests that fertility is declining in the country.

Calculating Rates

A rate provides information on the frequency of a demographic event, such as a birth, death, or migration. Demographers express rates as crude, general, or specific. A crude rate measures the frequency of a vital event occurring in the total population. General rates, such as the general fertility rate, limit the event to those persons at risk of the event such as women in their reproductive ages (15-49 years of age). Specific rates, such as the age-specific fertility rate, measure an event among a subset of the population at risk. The age-specific fertility rate measures fertility among women in specific age groups in their reproductive years.

Several types of rate calculations will be discussed including:

  • Crude rates
  • General fertility rate
  • Age-specific fertility rate
  • Total fertility rate
  • Infant mortality rate

Equation 3-11 provides the general form for a rate calculation.

Equation 3-11
Calculating Rates

U

Crude Rates: Birth and Death Rates

The crude birth rate, as shown in Equation 3-12, shows the frequency of births occurring among an entire population, while the crude death rate (equation not shown) shows the frequency of deaths for the total population. The crude death rate would include deaths in the numerator.

Equation 3-12
Crude Birth Rate

V

Crude birth or death rates are usually calculated for a period of one year. The denominator is the population at midyear, the point roughly where half of the year's changes in population would have occurred. Techniques to calculate the mid-year population can be found in Lesson 5: Estimating Population Size.

Changes in the age structure can alter the values of crude rates. All individuals including men, children, and the elderly are part of the total population. To understand changes in birth rates, it is best to use rates that control for age and gender such as the general fertility rate or the age-specific fertility rate. The remainder of the discussion of rates will focus on fertility. Migration and death rates are discussed in Lessons 7 and 8.

Why are planners interested in fertility levels?

Birth rates and the age structure of the population are highly related to one another. When birth rates are high, youth tend to comprise a high percent of the population. As a result, plans and resources must focus on meeting the educational, health, housing, and recreational needs of children. A young population will also produce more births since the next generation of young women will enter their childbearing ages in the next decade. Resources must continue to focus on meeting the needs of children, even when birth rates decline. Planners must therefore study fertility measures and the impact on the age structure of the population for several points in time.

General Fertility Rate

The general fertility rate is a more refined method than the crude birth rate. It eliminates distortions that may arise due to:

  1. Age structure
  2. Sex distribution in a population

The general fertility rate, shown in Equation 3-13, is used primarily to observe changes in births when planners have limited information.

Equation 3-13
General Fertility Rate

W

An example of the general fertility rate calculation is shown below.

Example of Equation 3-13
General Fertility Rate

X

Age-Specific Fertility Rates

Age-specific rates include the age of individuals in the calculation of rates for events such as births and deaths. Equation 3-14 presents the equation for the calculation of the age-specific fertility rate.

Equation 3-14
Age-Specific Fertility Rate

Y

An example of the age-specific fertility rate using data from Table 3-4 is shown below.

Example of Equation 3-14: Age-Specific Fertility Rate Among Women Ages 20-24

Z

The results show that there are 249.9 births per 1,000 women in that age group in that given year. Age-specific fertility rates are usually calculated for each age group provided that birth statistics are available by age of mother.

Total Fertility Rate

The total fertility rate indicates the average number of children that would be born to women during their lifetime, if the women conformed to the age-specific fertility rates. It provides insights into a country's fertility levels, as well as information on potential household size which has implications for housing needs of families. The total fertility rate is shown in Equation 3-15.

Equation 3-15: Total Fertility Rate

ZA

Table 3-4 provides data and examples for the calculation of both age-specific and total fertility rates.

 
Table 3-4: How to Calculate
Age-specific Fertility Rates and the Total Fertility Rate
Age Groups Births Females Age-specific
15-19
20-24
25-29
30-34
35-39
40-44
45-49
5,025
11,429
9,033
6,031
3,921
2,425
1,309
49,485
45,739
36,075
25,817
20,618
18,089
15,642
101.5
249.9
250.4
233.6
190.2
134.1
83.7
ZB
Calculations Column 2 Column 3 Column 4 =
Column 2 divided by Column 3 * 1,000
 

Infant Mortality Rate

The infant mortality rate is an important measure of the health and development of the infant population within a given locale. The infant mortality rate, as shown in Equation 3-17, is the number of deaths of infants under 1 year of age per 1,000 live births.

Equation 3-16: Infant Mortality Rate

ZC

Based on the 1998 Ghana Demographic and Health Survey, where information is presented on trends in infant mortality, the rate has declined from 99.6 per 1,000 live births in 1975, to 56.7 per 1,000 live births in 1998. This implies that more and more infants are surviving their first year of life. This infant mortality rate can also be compared with the under-five mortality rate, that is the total number of deaths to children under age 5 per 1,000 live births.

Ghana is also experiencing declines in under age 5 mortality, from 187.2 per 1,000 births in 1975, to 107.6 per live births in 1998 (calculation not shown). This implies that more and more children are surviving in the country. These children will require health and educational services. These rates can also be used in evaluation plans, specifically, to assess the quality of health care for infants, young children, and pregnant mothers.

Exercises

Questions 3-1 and 3-2

Age-specific fertility rates can be calculated for several points in time to explore trends in fertility among age groups. Table 3-5 presents the different types of fertility rates that have been discussed up to this point. The table presents age-specific fertility rates, the total fertility rate, the general fertility rate, and the crude birth rate for Ghana for three points in time, 1988, 1993, and 1998.

Question 3-1.
In general, which two rates and/or ratios are the worst indicators of fertility? Why?

  1. Crude Birth Rate
  2. General Fertility Rate
  3. Total Fertility Rate
  4. Age-specific Fertility Rate
  5. Child-woman ratio

Question 3-2.
The information in Table 5 indicates that fertility is declining in Ghana. Age-specific fertility rates show that women in all age groups are experiencing fewer births. The total fertility rate indicates that in 1998, the average number of births of women in their reproductive years is 4.5 children, a decline of close to 2 children per woman since 1988.

 
Table 3-5: Fertility Rates per 1,000 Women in Ghana, 1988, 1993 and 1998
Age Groups 1988 Ghana
Demographic and
Health Survey
1993 Ghana
Demographic and
Health Survey
1998 Ghana
Demographic and
Health Survey
      15-19
20-24
 25-29
30-34
35-39
40-44
45-49

Total Fertility Rate
General Fertility Rate
Crude Birth Rate
124
258
278
248
195
117
60

6.41
216.9
Not Available
119
231
244
215
163
99
29

5.5
178.3
36.1
90
192
206
183
143
79
16

4.55
154
32.7
 


a) What are the implications of fertility decline for planning?

b) Which of the following fields of planning will declines in fertility impact the most?

  1. Education planning
  2. Health care services
  3. Housing
  4. All of the above

Knowing the composition of a population helps planners determine both the current and future needs for services and demands on the region's infrastructure. The elements of population composition (or structure) include:

  • Age/sex distribution
  • Educational status
  • Employment status
  • Household size
  • Income
  • Martial status

Of these elements, household type and size and the age and sex composition of the population guide decisions on community needs including housing, health care, education, and recreation.

Household Structure

Households consist of people who reside in different types of living arrangements as indicated below.

A household may include:

  • One person who makes provision for his/her own food and other amenities for living
  • A group of related individuals who make common provision for food and other amenities for living
  • A family unit including an extended family
  • Unrelated individuals who are living together and sharing common provisions for food and other amenities

Information on the composition of the household and household size is usually found in census information. This information can also be obtained from sample surveys that are based on the entire population.

3.3 Population Composition

Population Pyramids 

The age and sex distribution of a population plays a major role in guiding decisions about the provision of services for different segments of that population. Planners have two simple tools to examine the age and sex distribution of a population:

  • A table showing the percent distribution of men and women in different age groups
  • A population pyramid

A population pyramid, also known as a horizontal bar diagram, is a graphic tool used to study the age and sex composition of a population. Its bars represent age groups beginning with the youngest ages at the base of the pyramid and the oldest age groups at the top. Males are represented on the left side and females are on the right side of the diagram. The age scale can be down the center axis or to the right or left of the pyramid. In most cases, 5-year age groups are used beginning with ages 0-4.

Population pyramids can be represented in absolute numbers or in percentages. When constructing a pyramid based on percent distribution, the combined total of males and females should be used in calculating percentages for age groups among males and females. One should not use the total population size for males to develop the percentages for male age groups. The percent distribution of males and females should be based on the combined population of all males and all females.

Population age pyramids may be used to:

  • Crudely observe the impact of fertility, migration and mortality on the population of a given locale.
  • Observe changes in the age and sex structure when pyramids are developed for at least two points in time.
  • Help planners observe future changes in the population. In this case, planners may compare a population pyramid that is based on recent census figures with one that is based on population projections.

Constructing a Population Pyramid

A population pyramid may be constructed with a spreadsheet program such as Microsoft Excel, or by hand with a ruler and graph paper. Instructions for constructing a population pyramid with a spreadsheet are included in Population Age Pyramid Construction and Data Acquisition. The following steps may be used to construct a population pyramid by hand. Table 3-6 provides data needed to construct a population age pyramid for the Volta Region of Ghana.

 
Table 3-6
Organizing Census Data for a Population Pyramid
Column 1 Column 2 Column 3 Column 4 Column 5
  % %
Ages Males Females Males Females
0-4
5-9
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85+
96052
96807
78864
67713
47232
37303
29672
23290
19551
19635
17193
11535
11440
8524
7861
4772
4187
5309
96409
94659
72404
60663
53767
45356
36543
28186
24877
23568
21199
14217
15465
10727
9261
5604
5229
6770
7.93
7.99
6.51
5.59
3.90
3.08
2.45
1.92
1.61
1.62
1.42
0.95
0.94
0.70
0.65
0.39
0.35
0.44
7.96
7.81
5.97
5.01
4.44
3.74
3.02
2.33
2.05
1.94
1.75
1.17
1.28
0.89
0.76
0.46
0.43
0.56
Total Population: 1,211,844
Source:
Population Pyramid for Volta Region, 1984
Statistical Service, 1984, Volta Region, Accra: Statistical Service
 

Step 1: Obtain census information for males and females by 5-year age groups.

Step 2: Draw 5 columns on a sheet of paper.

  • Title column 1 Age Groups. In this column write the 5-year age groups beginning with ages 0-4 and ending with age 85+.
  • Title column 2 Males and column 3 females. Write the census figures for each age group of males and females in columns 2 and 3.

Step 3: Title column 4 % Males and column 5 % Females.

  • Next, calculate percentages for each age group of males and females using the combined total population for males and females.
  • For example, to calculate the percent of females ages 0-4, use the total population for males and females in all age groups. This can be done using a hand calculator or spreadsheet. Most census reports present percent distributions by age and sex. The percent distributions can be used provided that they are based on the total population including males and females.

Step 4: Draw two lines on either graph paper or plain paper - a long horizontal line and a vertical line intersecting at the midpoint of the horizontal line.

  • At this intersection write 0 (zero)
  • From the right of the horizontal line, mark off percentages beginning with 2% and continue until 10%. Make the percent points equal distances apart.
  • On the left side of the vertical line, start with 2% and continue left until 10% is marked.
  • On the vertical line, begin equal distances apart with age groups beginning with ages 0-4 at the base of the line, and continue until age 85+ is reached.
  • On the left side of the vertical line, write Males and on the right side write Females. 

Step 5: Next use a ruler to make the horizontal bars.

  • Using the percent distribution for males and females in Columns 4 and 5, begin making horizontal bars that correspond to the percentage marked on the horizontal line. For example, for males ages 0-4, find the percent in column 4 and make a horizontal bar that reflects the percentage for that age group.
  • Do the same for females for that age group.
  • Continue until all of the bars for each age group are completed.

Reading a Population Pyramid

Fertility levels influence the shape of the pyramid for early age groups. A pyramid with a large base among the lower bars, or at the bottom, tends to reflect high levels of births within the population. Pyramids of this nature call attention to the need to provide a range of services to age groups 0-14 such as schools, primary health care services, and recreational facilities such as soccer fields.

In areas of heavy out-migration, pyramids tend to have smaller bars between the ages of 20–49. Cities, in particular, have large bars between the ages of 20–49 which reflect movement for jobs, education, and other opportunities. Heavy in-migration places tremendous demands on planners to provide housing, health care, schools, and basic infrastructure such as roads, electricity, and safe water to new residents.

Reading Figure 3-1

Figure 3-1 shows the population pyramid for data from Table 3-6. Observe the impact of mortality by looking at the top of the pyramid among the 65+ age groups. The bars at the top of the pyramid tend to be the shortest and reflect deaths among the population.

Figure 3-1:

Ghana Pop

The base of the pyramid indicates that there is a large number of youth between the ages of 0–9 among males and females. More males than females are leaving the region in their working years, 20–55. The top of the pyramid shows the impact of mortality on those 65+ for males and females. The pyramid clearly justifies resources for youth in the region. It also shows the impact of out-migration on the labor supply in the region. Planners may wish to develop programs to maintain or expand economic activities to discourage out-migration.

For a trend analysis, four pyramids should be constructed:

  1. One for the prior census
  2. One for 1984
  3. One for the present census of 2000
  4. One based on a projection of year 2005 or 2010

The four population pyramids will allow planners to observe changes over time in the age and sex distribution. The graphs can be used in part to justify the present and future allocation of resources to specific segments of the population.

Exercises

Questions 3-3 and 3-4

A planner is writing a development plan for a district. The planner must examine a range of rates, ratios and other measures to understand what is taking place. He/she is in the early stages of developing a demographic profile and has collected some information to start with. Help the planner think about additional information to add to the profile. Focus on how the information can guide planning decisions.

Use the data in Table 3-7 for the following exercises.

Table 3-7
Select Population Information in a District Demographic Profile
Information 1970 1984 2000
Population size

Annual rate of growth

Total fertility rate

Infant mortality rate

Percent age 0–14

Sex ratio

Percent rural

Population density per square km.
132,681

1.69

6.4

87

49

90

80

59
152,785

1.41

5.5

71

47

80

72

89
181,835

1.74

4.0

56

49

65

59

124
 

Question 3-3.
How can the rates, ratios, and other measures be used in planning?

Question 3-4.
What other types of population information should be added to the profile?

3.4 Conclusion

Lesson 3 introduced the tools and information suitable for creating a profile for a region, district, or, other locale. The lesson includes key demographic tools used to help guide planning decisions.

Think about other types of population-related information to be included in plans and planning related documents. Selection of population information should be based on the ability to assist in:

  • Development, revision or expansion of a given plan
  • Implementation of planned strategies
  • Evaluation of the plan

Identify information that will help you establish goals and objectives, and estimate the need for future services and facilities such as the number of schools, teachers, health care clinics, housing, and water consumption, to name a few. You can also select population statistics that can help you evaluate your plans. If the goal is to reduce infant mortality rates, this rate can be used as an indicator or evidence of the success of a primary health care plan.

A demographic profile should not be isolated in its own section of the plan. Present and discuss population information in all sections of the plan. For example, if revising a housing plan, discuss changes in the total fertility rate, changes in the age/sex distribution, and changes in household size both in the population section of the plan and in a discussion of projected housing needs.

Fertility measures such as the total fertility rate provide information on the average number of children women will have during their reproductive years. If developing a plan on expanding educational services, include information on fertility rates since it determines future numbers of youth. The number of new schools, teachers, and teaching materials will be based on information on the present and future size of youth in the given population.

Exercise Answers

Answer Question 3-1

a) Crude birth rate
The crude birth rate includes the total population including men, children and women who are beyond their reproductive years. A large percentage of men in the population can distort the rate, for example. To examine trends in fertility, its best to use rates that control for age and gender such as the general fertility rate or the age-specific fertility rate which are based on women in their reproductive years.

e) Child-woman ratio
The child-woman ratio is used in areas where information on the number of births is not available. The ratio is based on census data and not on actual births. It is based on those children ages 0–4 that were alive at the time of the census. Areas with high levels of infant mortality in particular may understate births in a given locale.

Answer Question 3-2

It takes 10-20 years before fertility declines require changes in local and regional planning efforts. The next generation of mothers has already been born and will add to the population once they enter their reproductive years. Planners need to continue focusing on meeting the needs of youth for the next decade.

Declines in fertility will not, however, have an immediate impact on the need for services for youth. In the long term (within the next decade) several sectors of planning may be influenced by reductions in fertility. Declines in fertility have implications for primary education facilities. If there are fewer children in the future, then there will be less need of primary education facilities and teachers.

Lower levels of fertility can also influence the provision of health care services for children and women in their reproductive years. Health planners may be able to reallocate resources to meet the health needs of different segments of the population. Declines in fertility also have implications for family size and consequently housing needs. Smaller families will require less shelter.

Answer Question  3-3

Table 3-8:
Answers to Question 3-1
Information Use in Planning
% Change Planners need to understand whether or not the total size is increasing or decreasing. They need additional information on the characteristics of the population that is growing or declining as well as the physical location where growth or decline is taking place.
Annual rate of growth Allows planners to understand the % at which the population is growing each year
Total fertility rate Provides insights on the average number of children that women in their reproductive years will have. Fertility and the age structure are related. If women are expected to have a large number of children, then the district must allocate much of its resources to services for youth, ages 0-14.
Infant mortality rate Use to establish objectives and evaluate the health component of the district plan, in particular. It can also be used to measure development efforts. High levels of sanitation, safe water, adequate housing, educational and employment opportunities for parents, and accessible primary health care influence the levels of infant mortality
% Of population ages 0-14 This %, if measured for several years, provides insights on the amount of resources to be devoted to meeting the needs of youth. The information can be used in identifying problems, setting goals and objectives and developing implementation plans
Sex ratio Provides some insights on migration in the district, especially if the ratio is calculated by 5-year age groups. It crudely indicates if males are moving out or into the district.
% Rural Rural populations have different needs than urban populations. This percentage, if calculated for several points in time, allows planners to observe how the district is changing. Planners will need to determine whether or not to expand rural development efforts or to increase services in urban areas.

Answer Question  3-4

Information Selection

Select population information based upon its role in guiding planning decisions. For a better understanding of the residents' characteristics include:

  • Age-sex distribution
  • Household size
  • Educational attainment
  • Occupation
  • Income levels

Housing Needs

To plan for housing needs, the following information is needed. Remember: Age and sex distributions can be used to develop population pyramids for several points in time.

  • Age distribution
  • Sex distribution
  • Fertility indicators (age and sex structure is strongly influenced by fertility levels)
  • Changes in household size
  • Changes in household composition
  • Census data on housing quality and amenities

Information on the age and sex distribution of a population is critical

when planning for the housing needs of different segments of that population.

Need to Know

Planners need to know where growth is taking place within the district. They can calculate percent change for each sub-area of the district and place the information on a map. The location of new or expanded services and infrastructure is determined by changes in the location of population. If migration information is available from census information or sample surveys, planners can assess population movements and the impact on the sectors of the development plan.


This is not a complete list of answers. The intent of this exercise is to encourage thinking about the types of population information needed to guide planning decisions.

References

George W. Barclay, Techniques of Population Analysis (New York: John Wiley and Sons, 1958) 16–55.

Arthur Haupt and Thomas T. Kane, The Population Handbook (Washington. D.C: Population Reference Bureau, 1978).

James C. Raymondo, Population Estimation and Projection (New York: Quorum, 1992) 107–108.

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