Population Pyramids and Demographic Transition Model Population changes over time and space. 2. Population change can be shown on two models.

The population pyramid displays the age POPULATION STRUCTURE The population pyramid displays the age and sex structure of a country or given area OLD DEPENDANTS ECONOMICALLY ACTIVE YOUNG DEPENDANTS Population in Five Year Age bands FEMALES To the right MALES To the left Usually, but not always, in % to make for easier comparisons between countries

What Population Pyramids Show Us KEY The overall shape of the population pyramid can indicate whether it is an Economically More Developed Country or Economically Less Developed Country Economically More Developed Country Less slope of pyramid indicate the death rate height of graph can indicate life expectancy (ignore the very thin end of the wedge as occurs on graph B as these people are a definite minority) proportions of men and women can suggest male or female migrations "kinks" indicate dramatic reductions in birth rate or increases in death rate in the past width of the base is related to birth rate/fertility rate area of graph indicates total population - compare areas of different population age groups or different sex on one graph

The DTM (Demographic Transition Model) The three key components to pay attention to in the Demographic Transition Model are: Birth Rates Death Rates Total Population The vertical on the graph is rate per 1000 and the horizontal is time.

(Demographic Transition Model) The DTM (Demographic Transition Model) Stage A Both high birth rates and death rates fluctuate in the first stage of the population model giving a small population growth (shown by the small total population graph).

(Demographic Transition Model) The DTM (Demographic Transition Model) Stage B Birth rates remain high, but death rates fall rapidly causing a high population growth (as shown by the total population graph).

(Demographic Transition Model) The DTM (Demographic Transition Model) Stage C Birth rates now fall rapidly while death rates continue to fall. The total population begins to peak and the population increase slows to a constant.

(Demographic Transition Model) The DTM (Demographic Transition Model) Stage D Both birth rates and death rates remain low, fluctuating with 'baby booms' and epidemics of illnesses and disease. This results in a steady population.

(Demographic Transition Model) The DTM (Demographic Transition Model) Stage E? A stage 5 was not originally thought of as part of the DTM, but some northern countries are now reaching the stage where total population is declining where birth rates have dropped below death rates.

Combining Both Models

Population Pyramids related to the Demographic Transition Model Stage 1 Stage 2 Stage 3 Stage 4 IMPLICATIONS Both birth rates and Death rates are High, so population growth rates are slow but population Is usually restored Due to high birth Rate. Short life Expectancy EXAMPLES: Afghanistan, Ivory Coast Population starts to grow at an exponential rate due to fall in Crude Death Rate. More living In middle age. Life expectancy rises Infant mortality rate falls. EXAMPLES: Jordan, Thailand Population continues to grow but at slower rate. Low C Death Rate. Dramatically declining Crude Birth Rate. EXAMPLES: Ireland, China, New Zealand Low Crude Birth Rate and Crude Death Rate Higher dependency ratio and longer life expectancy Crude Death Rate does Rise slightly because of The ageing population EXAMPLES: United States, Japan There is some merit in including or considering a Stage 5 today with a declining population