GEOG3205
Why do a Census?
Census Limitations - Cost - Complexity - Non-response Census Alternatives: - Long form/short form - Population Registers: combine with Surveys - Rolling Census
Fertility differentials
LOW fertility - urban - educated - higher income - secular - liberal HIGH fertility - Rural - uneducated - lower income - religious - conservative VARIABLES preceding progression to 3rd birth - less than 28 when 2nd child was born - had defacto relationship - interval between 1st and second child was 2 years or less - first birth unplanned -catholic
The Basic Demographic Equation
Pt+n = Pt + (B - D) + (I - O) - Pt+n is population at time t plus n years - Pt is population at time t - B is births occurring between t and t+n D is deaths occurring between t and t+n AND for Individual countries, or regions - I represents gains from immigration - O represents losses through emigration
Ways of counting in demography
Two main alternatives: - De facto = count of people where they are --- Includes all visitors to an area (international and domestic) --- Excludes people who were elsewhere - away from home - De jure = count of people where they usually live Australian Census --- counts people in their actual location on Census night --- 'de facto' enumeration, not 'de jure'', --- but, also generates a set of 'de jure' figures by --- de jure basis is now the default framework for Census data
*** Flow Data - Demographic events
Vital Events - births, deaths, marriages, divorces - parish registers since C14 - Centralised recording since mid C19 - Registrars of BM&D in each State - standard classification criteria - eg ICDN Migration Flows - Inwards and outwards movements - Captured in immigration passenger cards --- Not all countries collect these data
Demographic basics
What is a Population? - A population is "the collection of persons alive at a specified point in time who meet certain criteria" What criteria? - Refers to a specific point in time - Generally a particular Location or Area - May be specific characteristics..... -----Eg ------ Population of Queensland on 9 August 2011 ------ Indigenous population of the NT as at.... ------ Population aged 50 and over born in Estonia ------ Population on the St Lucia Campus
The role of migration
**- Migration as the principal demographic process underpinning regional and local population change - 17% of Australians change residence each year; - 42% over five years - Migration highly selective, by age Key patterns: -- North and west -- Inland to coast -- Suburbanisation -- Inner urban renewal
Why focus on local areas in demographics?
**- because places differ - Spatial heterogeneity --- population characteristics vary across space - Occurs at a variety of scales --- local/regional/state/national
What is Applied Demography
- "Applied demography is the subfield of demography focusing on practical applications of demographic materials and methods" - "Applied demography is that branch of the discipline that is directed towards the production, dissemination, and analysis of demographic and closely related socio-economic information for quite specific purposes of planning and reporting" - "... the subfield of demography concerned with the application of the materials and methods of demography to the analysis and solution of the problems of business, private nonprofit organisations and government, at the local, national and international levels, with a primary orientation toward particular areas and the present and the future
Modelling local population dynamics - Life cycle of suburbs
- A life cycle of suburbs? - Hypothesis that suburbs proceed through a cycle of birth, maturity and old age followed by rejuvenation Seductive hypothesis and identifiable in some localities STAGES 1 Initial settlement linked to couple formation 2 Family formation 3 Child-launching 4 Empty nest 5 Widowhood & disability 6 Household dissolution 7 Rejuvenation - return to stage 1 Rarely evident in Practice - Areas rarely settled at same time - Housing needs change over the life-course - Substantial turnover via migration - Cycle interrupted by shifts in land use - Areas assume unique roles in urban metabolism
How do we count people in demographics?
- A population is "the collection of persons alive at a specified point in time who meet certain criteria" Criteria includes: --- Population statistics refer to a specific point in time --- Generally refer to a particular Location or Area --- May be confined to those with specific characteristics - Everyone is counted in the Census Everyone, People away from home, People in prison, Armed forces, Overseas visitors, Temporary residents, People on the move? Foreign diplomats are NOT counted.
*** Lexis diagram -- PRINT DIAGRAM LECTURE 1
- Age-Time plan depicting the relationship between age, period and birth cohort. - Age and time divided into equal intervals - Lifelines show individual aging - Events fall into age time intervals - Links population stocks and flows - Framework for the assembly and analysis of demographic data Lexis Diagrams Help Distinguish three types of Effects in Demography: 1. Age effects 2. Period Effects 3. Cohort Effects
ERP - Estimated resident population
- Australia's 'official' population figure - Includes adjustments for visitors and for undercount - 'Benchmarked' at the Census - every five years - Updated by rolling forward to give annual estimates for each State, region, LGA - But the annual ERP only gives - total population and age/sex composition - no other characteristics
Comparing population data
- Caution needed in comparing different types of population data - ERP gives most up to date figures - annual time series, but only age and sex - Census data give detailed population characteristics but include visitors - Usual residence data now most widely used, ... - In Tourist Areas, Visitor Numbers may be significant for planning. - Need to look at all three figures and understand differences in what they include
Why do Census and population estimates
- Census provides an occasional benchmark figure with population characteristics - Population estimates provide estimates for non-Census years --- may have some basic characteristics --- less spatial detail --- Fewer characteristics --- Usually produced by some mathematical method using symptomatic data
The determinants of fertility
- Cultural - Socio-economic - environmental - Age at marriage/ sexual union - monogamy/ polygamy - widowhood, divorce - spuosal separation - coital frequency - post birth abstinence ---- These all affect exposure to intercourse - natural sterility - pathological sterility - locational amenorrhorea - contraceptive use ----- these all affect contraception - Spontaneous abortion - induced abortion --- these all affect pregnancy outcome and therefore fertility of live births
The demographic transition
- Describes the transition from traditional societies in which birth and death rates are high but in balance, through epochs of rapid population growth, to the situation characteristic of modern, industrial societies where fertility and mortality come back into equilibrium at new low levels GRAPH
Models of City Structure: The Residential Mosaic Within Cities
- Ethnicity - nodes - Family status - concentric zones - Socio-economic status - sectors - Represents a mix of three major dimensions of population and households in space
Limitations on fertility
- Even in pre-transitional societies, fertility never reached this "natural level" - Hutterites (10 children per woman) - Niger (7.15 children per women) Why not? reach natural level? - Natural sterility - Maternal mortality (Afghanistan (2008) : 1400 deaths per 100,000 live births) - Low life expectancy at birth (E0) (Afghanistan 43.8 years) - Poor nutrition - Humans have always exerted some control over fertility
Housing location and family life cycle
- Family Transitions Alter Housing Need which Plays a Key Role in Shaping Cities
Fertility and fercundity
- Fecundity = the physiological capacity of a woman (or man or couple) to produce a live child) - Fertility = the actual reproductive performance of an individual, a couple, a group or a population - Sterility = the complement of fecundity - physiological incapacity to bear children
Differences in age structures reflect:
- Fertility - Mortality - Migration - Ageing - Timing of settlement --- Shown in population pyramid
History of Australian Census of population and housing--
- First National Census under Census and Statistics Act in 1911 - Required for electoral purposes, revenue sharing, and planning - Objective: 'to measure the number and characteristics of people and the dwellings in which they live' - Three areas of inquiry individual/family/dwelling -- Persons (individuals) -- Families and households (derived from question on relationships) -- Dwellings - Made up of 60 substantive questions
History of Australian Census of population and Housing
- First simultaneous Census in 1881 - First National Census under Census and Statistics Act in 1911 - Required for electoral purposes and revenue sharing, as well as planning - Objective: 'to measure the number and characteristics of people and the dwellings in which they live' - Three areas of inquiry individual/family/dwelling - Variation in topics over time - Was 10 year gap between census, then 12 & 14. Now consistently 5 year gap.
Measuring association - Index of dissimilarity
- Index of Dissimilarity: -- x is the percentage of sub population X in category i -- y is the percentage of sub population Y in category i Key features: - Varies between zero and 100 - Value of zero implies complete congruence - identical distributions - Value of 100 implies complete apartheid - Intermediate values indicate proportion of one population that would need to relocate to match the other distribution - Can also be used to measure dissimilarity between characteristics of two populations - eg birthplace composition of Brisbane cf Sydney FORMULA
Similar indices for comparison - Index of Redistribution - Index of Concentration
- Index of Redistribution - compares distribution of one variable between two points in time • xi is the percentage of sub population in area i at time t • yi is the percentage of sub population in area i at time t+n - Index of Concentration - compares distribution of a variable with distribution of area • xi is the percentage of sub population in area i • yi is the percentage of total territory or land in area i FORMULA
Conclusions of spatial patterns and processes
- Key aspects of local demographic change -- Population growth and decline -- Demographic processes - births, deaths, internal migration, international migration, population ageing -- Population momentum -- Historical context of settlement -- Role in the settlement system and space economy - Key issues -- Use appropriate demographic measures -- Focus on key characteristics -- Identify role the area plays in its region -- Make contextual comparisons -- Place in theoretical framework -- Refer to simple social and spatial models
Measuring association - Location Quotient
- Location quotients: compares 2 percentages/ proportions LQ = Xi / Yi --Xi is the percentage for the first population --Yi is the percentage for the second population ---- Professionals: Brisbane 21.3%; Gold Coast 17.5% ----LQ=21.3/17.5; 1.2 - Choose reference population wisely!
Why is Demography Important
- Major aspect of global, regional and social change population growth, ageing, immigration, development - Drives financial allocations, underpins social policy - eg pensions; electoral disbursements - Important for business - select sites, locate customers, identify markets - Provide services and facilities - eg schools, health care, aged care
Census Geography
- Nation - State - Statistical Division - Local Government Area LGA - Statistical Local Area SLA - Census Collection District CD
Linking spatial structure and demographic composition
- Places (towns, cities) fill particular roles within the national space economy - In a similar way, suburbs fill particular roles in the urban spatial structure - At the regional or national level, population dynamics determine the nature of housing demand - At the local level, the housing determines the characteristics of population and households
A household is made up with
- Private dwellings and non-private dwellings (institutional) - Private dwellings - occupied and unoccupied - OPD=Household - Households: Family and Non-family
The basic demographic equation - detailed
- Pt+n =Pt +(B-D)+(I-O) - Pt+n is population at time t plus n years - Pt is population at time t - B is births occurring between t and t+n - D is deaths occurring between t and t+n - I represents gains from immigration - O represents losses through emigration - B - D = Natural Increase (can be negative) - I - O = Net Migration (can be negative) ** See example on printout
Census trends worldwide
- Recommend decennial - Sporadic in many countries - Interrupted by war, etc - Some partial coverage - Replacement by registers, surveys - Length and topics vary widely
Spatial variations in mortality in Australia
- SMRs - Standardised Mortality Ratios - Control for differences in population age structures - Calculated by applying national death rates to regional/local populations, to generate 'expected deaths' SMR = observed deaths / expected deaths x 100 SMR > 100 - higher than expected SMR < 100 - lower than expected
*** Types of demographic data
- Stocks - count of numbers or characteristics at a particular point in time - eg Population Census - Flows - count of events occurring in a defined interval - --- eg births, deaths Pt+n = Pt STOCKS + (B - D) + (I - O) FLOWS
Natural fertility
- The level of fertility reached in the absence of any attempt to limit child-bearing by Malthusian or neo-Malthusian means -- Assume that the reproductive span (ability to bear a child) extends from age 15 to age 49 (from menarche to menopause) -- Each pregnancy lasts ~9 months (gestation) -- Average of 18 months between the end of one pregnancy and the beginning of the next -- Then... each women could bear a child every 2.2 years The result.....16 children per women
do SLAs or LGA represent communities?
- The nature of 'community' - communities of interest - shared goals or attributes - may not be spatially contiguous - Spatially defined communities --- by reference to convenient statistical or administrative boundaries - eg neighbourhoods, suburbs, villages - Cluster analysis --- statistical technique to group similar zones together - The anulus approach --- circle of defined radius around a specified centroid
Practical reasons for focusing on local areas - why be interested?
- Understanding needs --- needs related to population composition - Targeting services --- efficiency and equity in allocation --- withdrawal as well as placement of services - Identifying markets --- locations for advertising, sales campaigns, etc
Causes of spatial variations
- proportion of women ever married - proportion of women with children and average issue per woman
3 counts of population in Australia
1. Census Count - Count of all people in an area or region - Includes visitors from elsewhere in Australia - [832,263 people (4.0%) away from home in 2011] - Includes overseas visitors - but separately identified 2. Usual Residents - Excludes visitors from overseas - Excludes visitors from elsewhere in Australia - Includes residents temporarily away from home 3. Estimated Resident Population - Australia's 'official' population estimate - Builds on Usual Residents - Adds an adjustment for undercount at the Census (people missed) - Adds an estimate of residents temporarily overseas - Forms the basis for inter-censal or post-censal estimates - Census figures are 'rolled forward'
How do populations change?
1. Natural increase (births and deaths) 2. Migration - inwards or outwards 3. Ageing (each year, everyone gets a year older...!)
What do we measure in demographics?
1. Population Size - Current, Past, Future 2. Population Characteristics- Age, sex, occupation, birthplace, etc 3. Living arrangements- Type of family/household/ Type of housing 4. Vital Events- Births, Deaths, Marriages... 5. Migration- Arrivals/departures - domestic/international 6. Geographic location- Position in space or origin/ destination
What drives the difference? - Sources of spatial variation - 2 forms -- basic demographic equation
1. Variations in fertility and mortality --- patterns and extent 2. The effects of migration --- Volume, direction and composition --- migration as a selective process 3. Local population ageing / population momentum --- local age structure reflects demographic history --- Life course 4. Local role in the regional space economy --- inner cities as foci for young singles --- resource regions attract employed workers 5. Local impacts of national trends --- eg immigrant enclaves
What is a cohort?
A group of people who experience a common event eg people born during a given interval: - Australian birth cohort of 1982 - Australian baby boom cohort (born 1946-65) - Queensland marriage cohort of 2007 - UQ Masters graduation cohort of 2011 - GEOG3205 class of 2014 Cohorts are closed: membership is gathered at the start and then the club is closed and the number of members decreases with the passage of time
Sources of population data & emerging sources
CURRENT - Censuses - A complete enumeration of the population of a country, region or group - began around late C18, - Some quinquennial, some irregular - Population Registers - continuous roll, regularly updated - Generally includes 'all' residents or citizens - Widely used in Europe, but also Australia - Demographic Surveys - Sample basis - focus on aspects of demographic behaviour - Registers of vital events ---- eg births, marriages, deaths, immigration EMERGING - Commercial data - Acorn, Experian - Mobile phone records - witter, Google, Facebook
Census Counts Census usual residents Estimated Resident Population
Census Counts - Usual residents counted at home on census night - Count of visitors from other parts of Australia - Count of visitors from overseas Census usual residents - Usual residents counted at home on census night - Usual residents counted somewhere else in Australia on census night Estimated Resident Population ERP - Usual residents counted at home on census night - Usual residents counted somewhere else in Australia on census night - Estimate of usual residents overseas on census night - Estimate of net underenumeration - Census night to mid-year timing adjustment
Definition of FAMILIES & HOUSEHOLDS
FAMILY - A family is defined by the ABS as two or more persons, one of whom is at least 15 years of age, who are related by blood, marriage (registered or de facto), adoption, step or fostering, and who are usually resident in the same household. - Each separately identified couple relationship, lone parent-child relationship or other blood relationship forms the basis of a family. HOUSEHOLDS - Some households contain more than one family. - Non-related persons living in the same household are not counted as family members (unless under 15 years of age).
Factors Affecting the Settlement Distribution of Immigrants - Four Basic models of ethnic population distribution and redistribution
Factors Affecting the Settlement Distribution of Immigrants - Timing of settlement - Nature of migration - visa class - Housing market at time of arrival - Ability to speak English - Extent of cultural difference - Size of group - Assets Four Basic models - Model A - Settlement pattern on arrival similar to native born - Germans, New Zealanders - Model B - Immigrants tend to concentrate in small number of specific ecological niches on arrival, but subsequently disperse - Scandinavians - Model C - Initial settlement concentrations maintained, though they may 'migrate' - Italians, Greeks - Model D - Settlement pattern relatively dispersed on arrival, but subsequently becomes concentrated due to 'gravitational migration' - Vietnamese
What is Demography
Greek words - demos (people) - graphy (branch of knowledge of a particular science) - "Demography is the scientific study of human populations." - "Demography is the scientific study of human populations primarily with respect to their size, their structure and their development." - "Demography is the study of populations, their size, distribution, and composition, and the immediate causes of population change - births, deaths and migration."
Explaining spatial variations in mortality
HIGH mortality - inner/urban - rural/ remote - low income - uneducated - unemployed LOW mortality - Suburban - regional centres - high income - educated - employed - Many of the differentials reflect socio-economic status - if you want to live a longer life then: --- Get your degree --- Live in a pleasant suburban area --- Get a job --- and make sure it pays well!
Process of population change (Basic demographic equation) -- DIAGRAM
IN - Births - Immigration OUT - Deaths - Out-migration - Net migration = immigration - outmigration - Natural population change = Births - deaths
HOUSEHOLDS
Importance of household demography - Demand for housing - Demand for other goods & services consumed on a household basis What is a household? - A household is defined as one or more persons, at least one of whom is at least 15 years of age, usually resident in the same private dwelling. Under this definition, all occupants of a dwelling form a household and complete one form. Therefore, for Census purposes, the total number of households is equal to the total number of occupied private dwellings as a Census form is completed for each household from which dwelling information for the household is obtained. - Up to three families can be coded in one household: the primary family (usually the first listed on the Census form, or the one with dependent children), and up to two others (referred to collectively as secondary families, and individually as second and third families).
Calculating Population Growth Rates
Rate of population growth (% increase) - R = P t+n - Pt / Pt x 100 Annual average rate of population growth % - R = sqroute of n Pt+n/ Pt - 1 x 100 * this is good for making comparisons for equal time intervals such as 2001 - 06, 2006-11, but doesnt work when not equal ** See printout for example of problem
Problems and issues in spatial analysis
The Ecological Fallacy - Fallacy in the interpretation of statistical data - that the individuals within a region exhibit the aggregate characteristics of the region Modifiable Areal Unit Problem (MAUP) - Results of analysis depend on the zonal boundaries: » Scale dimension - results depend on the number of units into which space is divided » Aggregation dimension - results depend on the way that boundaries are drawn -ie the way that space is divided.
Age, Period & Cohort in Demography
Why is age important? - Major determinant of demographic behaviour - Sometimes follows biological rules - Sometimes reflects social behaviour - Different ages exhibit very different behaviours Why is period important? - External factors that influence behaviour in a particular segment of calendar time. --- Examples: war, depression, period of social change - Can stimulate or depress particular demographic processes Why are cohorts important? - Cohorts share similar experiences as they pass through the life course - Cohorts have some key feature, experience or characteristic in common - Cohorts reputedly display particular types of behaviour popular demographics - eg Gen x
