so it's no secret that the populations of countries around the world change over time today we can see that some countries are experiencing population boom and some countries are experiencing a population decline but the real question is why what historical and contemporary factors have and could impact a population's trend now before we explore this question we have to review a couple important terms that you're going to be hearing not only throughout this video but throughout the rest of the course crude birth rate is the total number of live births in a year for every 1 000 people alive in a society the crew death rate on the other hand is the total number of deaths in a year for every 1 000 people alive in the society then total fertility rate is the average number of children a woman will have in her lifetime next is infant mortality rate which is the total number of deaths for people under the age of one in a year for every one thousand live birth and lastly natural increase rate which is sometimes referenced as rate of natural increase and this is a percentage by which a population grows in a year to find this you take a society's CBR and subtracted CDR one thing to remember is that the nir only looks at natural births and deaths it does not take into account migration so just because a society has a negative nir it may not mean that the population is shrinking countries that have a high nir will take less time to double their population which could put a strain on the country's infrastructure and system traditionally we can see that areas that have less economic development often have a higher natural increase rate as societies develop gain access to more modern medicines continue to urbanize and provide more opportunities for people to participate in the society they start to see their growth rate slow historically events such as the Industrial Revolution and medical Revolution led to population boom as Society started to see a higher life expectancy and lower infant mortality rate today we can see that population Dynamics are heavily influenced by a variety of different social cultural political and economic factors social factors such as investment in health care and education allow for a society's life expectancy to increase while at the same time can also decrease a society's total fertility rate and infant mortality rate when a society promotes education for men and women they often see their TFR decrease this is because as more people get an education they gain new skills and abilities that allow them to participate in the workforce which pushes back a person's timeline for having children if we look at a society's cultural values we can examine how a society views the different Sexes and what gender roles are established and promoted within a society societies that do not allow women to participate in the economy attend school and view individuals with traditional gender roles tend to have higher tfrs and a higher nir but cultures that open up more opportunities for women in school society and the economy tend to see their economies grow their TFR decrease and their natural increase rate level as societies develop economically and become more connected to the global Community they often see their cultures shift as people become more aware of other cultures around the world as societies grow and develop we start to see more people moving to urban areas jobs start to shift out of the primary and secondary sector of the economy and move into the tertiary sector these economic changes influence a society's culture birth rates and the day-to-day lives of everyday people developed economies with high rates of urbanization will often see smaller family sizes since there's more of a focus on starting a career and less of a need for a larger family family sizes also tend to decrease since larger families start to become less practical due to the cost of housing day care and all of the other expenses that go along with having children oftentimes more developed economies will start to see more individualistic and Global cultures develop as more individuals focus on individual achievements and modern Trends whereas less developed economies that have an agricultural base economy traditionally 10 to have larger family sizes these larger families are not only due to more traditional gender roles but also due to economics as well children often help around the home and the farm providing economic benefits for families changing gears and looking at the government we can see how the government can have an impact on population as well when governments pass certain laws it can either create more opportunities for Citizens and protect an individual's rights or new laws could actually restrict citizens or deny citizens certain rights if a government passes laws or uses propaganda that promotes Family Planning the use of contraceptives or reduces the cost of daycare and education it will decrease a population's growth rate but if a government restricts contraceptives offers a little education on Family Planning and does not provide rights for women they may see their population growth rate increase when it comes to government policies and birth rates we can see policies fall into two categories pronatalist policies which promote citizens to have more children and anti-natalist policies which which seek to reduce birth rate we will talk more about these policies in our unit 2 topic 7 video well just like that another topic review video is done now don't forget if you found value in this video consider hitting that subscribe button and if you need more help with AP Human Geography consider checking out my ultimate review packet it's a great resource that'll help you get an A in your class and a five on that National exam as always I'm Mr sin thank you so much for watching and I'll see you next time online