Demog HW#1 Final

Sex, Death, and Data Sociology/Demography C126 UC Berkeley, Fall 2023 Assignment 1 Due September 6 1. (5 points). To gain an appreciation for the size of the number 1 billion (1,000,000,000), come up with 3 ways to understand/visualize it. a) A paper clip weighs ~1 gram. 1 billion paper clips would weigh 1000 tons, which is around the weight of a cargo ship. b) 1 billion seconds is around 32 years. c) 1 cm is about the width of our thumb. 1 billion cm is ~6214 miles, which is around the same distance between my hometown (Zhejiang) to SF (6237 miles). Flying from Zhejiang to SF would take about 12 hours. 2. (5 points). If all people ever born who have died roam among us as ghosts, what’s the ratio of ghosts to living people? (You can find the number of people who have ever been born on the internet.) a) The Internet states that 117 billion people have been born in total. The current population is 8 billion. The ratio of ghosts to living people would be: (117 - 8) : 8 → 109 : 8 This ratio comes down to around 13 ghosts per 1 alive person. It is said that you know your house is haunted if the lights flicker on and off. Do you think that most ghosts would know how to work a light switch based on their lived experience? If not, why not? b) The electric switch was invented in 1884, so most ghosts would know how to work a light switch. Shown by the table in question 3, the population has increased significantly since the 1850s. There seems to be a lot more people born after 1884 than before, so most ghosts would know how a light switch works. 3. (10 points) . Using these estimates of the human population, answer the following questions. Year Estimated human population Annual growth rate from previous time point Column 1 Column 2 Column 3 Column 4 Human population bottleneck at the end of last ice age -100,000 10,000 Beginning of agricultural revolution -10,000 10,000,000 7.68 x 10^-5 1 AD 250,000,000 3.22 x 10^-4 Start of the global agriculture 1650 500,000,000 4.20 x 10^-4 1750 750,000,000 4.05 x 10^-3 1850 1,200,000,000 4.70 x 10^-3

1900 1,650,000,000 6.37 x 10^-3 Start of the public health evolution 1950 2,500,000,000 8.31 x 10^-3 1975 4,100,000,000 1.98 x 10^-2 1990 5,300,000,000 1.71 x 10^-2 2000 6,140,000,000 1.47 x 10^-2 2010 6,970,000,000 1.27 x 10^-2 2020 7,820,000,000 1.15 x 10^-2 Today 2023 8,045,000,000 9.46 x 10^-3 a. Calculate the annual population growth rates for all intervals between two consecutive time points, starting from the interval between 100,000 BCE and 10,000 BCE. ( Fill out column 4 ) b. Use the growth rate you calculated above for the period from the end of the last ice age bottleneck (100,000 BC) to the agricultural revolution (10,000 BC). What would the human population be today if the agricultural revolution hadn’t happened, and that growth rate had continued to the present year? i. 25,284,618 c. Use the growth rate you calculated above for the period on the eve of the global agricultural evolution in 1650 (between 1AD and 1650). What would the human population be today if the global agricultural evolution hadn’t happened, and that growth rate had continued to the present year? i. 584,798,942 d. Use the growth rate you calculated for the eve of the public health evolution in 1950 (the growth rate between 1900 and 1950). What would the human population be today if the public health evolution hadn’t happened, and that growth rate had continued to the present year? i. 4,585,528,141 e. Midway between 1950 and 1975, the human population growth rate hit its peak. What would the human population be today if the growth rate hadn’t declined, and the growth rate you calculated for 1975 had continued to the present year? i. 10,608,873,060 f. If our current population growth rate continues, what year will we reach 9 billion people? Do you think we will reach 9 billion before or after that date? i. We will reach 9 billion people in around 12 years, so in 2035. I think we will reach 9 billion after that date because I think the population growth rate will continue to decrease. 4. (10 points). This graphic about the demographic transition is everywhere. Its examples of countries at each stage are very outdated.