Demographic cycle The history of world population since 1650 suggests that there is a . demographic cycle of 5 stages through which a nation passes: (1) FIRST STAGE (High stationary) This stage is characterized by a high bih rate and a high death rate which cancel each other and the population remains stationary. India was in this stage till 1920. (2) SECOND STAGE (Early expanding) The death rate begins to decline, while the bih rate remains unchanged. Many countries in South Asia, and Africa are in this phase. Bih rates have increased in some of these countries possibly as a result of improved health conditions, and shoening periods of breast-feeding (3) THIRD STAGE (Late expanding) The death rate declines still fuher, and the bih rate tends to fall. The population continues to grow because bihs exceed deaths. India has entered this phase. In a number of developing countries (e.g., China, Singapore) bih rates have declined rapidly. (4) FOUH STAGE (Low stationary) This stage is characterized by a low bih and low death rate with the result that the population becomes stationary. Zero population growth has already been recorded in Austria during 1980-85. Growth rates as little as 0.1 were recorded in UK, Denmark, Sweden and Belgium during 1980-85. In sho, most industrialized countries have undergone a demographic transition shifting from a high bih and high death rates to low bih and low death rates. (5) FIFTH STAGE: (Declining) The population begins to decline because bih rate is lower than the death rate. Some East European countries, notably Germany and Hungary are experiencing this stage. Demographic cycle is based on : Demographic gap DG = Crude Bih Rate (CBR) - Crude death rate DG stas increasing : Early stage II (Early expanding phase) DG is Maximum : Late stage II (Early expanding phase) DG stas declining : Early stage III (Late expanding PHASE) DG is negative : Stage V (Declining phase) DG is Narrow : Stage I (high Stationary) ; Stage IV (Low Stationary) Ref: Foundations of community Medicine, GM Dhaarb& I Robbani, 1st edition Park 25th edition Pgno : 530