Comparing Demographics

1. Comparing Demographics Patricia Jancova Penny Hausher Block:1

2. Background • The U.S. has taken a census of its population every ten years since 1790 • The most recent census available to us at present is the 1930 census, due to a 72-year privacy restriction • From 1790-1840, only the head of household is listed • The number of household members are listed in selected age groups • In U.S. census records the questions vary from year to year and in state censuses, from state to state • Census records can provide the building blocks of your research, and confirm information • Details provided are: • Names of family members • Ages • Birthplaces • Residence • Occupation • Immigration • Citizenship details • Marriage information • Military service

3. Why Demographics? • We were inspired to explore this topic after seeing an insert from a recent National Geographic Magazine • A yearlong series on the global population

4. Data Collection • Most of our data collection occurred in center-city Philadelphia • Three locations: Market East Station, Rittenhouse Square, and City Hall • Tuesday after school~5-7 • Systematic Sample: every other person • Variables: sex, age group, ethnicity, Philly’s gear • Data on U.S., PA, and world statistics came from online sources 117 117

5. Variable Specifics • Ethnicity: • White • Black • Hispanic • Other • Asian, Indian, Native American, mixed, etc. • Age Structure: • Young: (1-14) • Middle: (15-64) • Old: (64+)

6. Ethnicity Data 117 51 17 15

7. Comparison of Ethnic Distributions Conclusion: the ethnicity of the entire Philadelphia population roughly matches the ethnicity distribution of the US

8. GOF of Ethnicity Distribution of Philadelphia The distribution of ethnicity fits the expected distribution The observed H distribution does not fit the expected distribution Conditions: Check Ethnicities are categorical Assume Representative All expected ≥ 5 State Categorical data SRS All expected counts are ≥ 5

9. GOF of Ethnicity Distribution of Philadelphia P(x2 > 38.7777│df=3)=1.9344x10-8 • We reject the Ho because the p-value of 1.9344x10-8 < α=.05. We have sufficient evidence that the distribution of ethnicity for Philadelphia does not fit the expected distribution of the US.

10. Literacy Rate Data • 13 Bahrain 88.8% • 88 Kazakhstan 99.6% • 9 Australia 99% • 140 Poland 99.3% • 161 Somalia 24% • 122 Namibia 88% • 157 Singapore 94.4% • 103 Macedonia 97% • 25 Brunei 94.9% • 169 Sweden 99% • 96 Lebanon 89.6% • 111 Mauritania 55.8% • 131 Norway 99% • 126 New Zealand 99% • 165 Sri Lanka 90.8% • 86 Japan 99% • 166 Sudan 60.9% • 70 Guatemala 73.2% • 152 Saudi Arabia 85% Claim: average world rate < US rate • Average Literacy Rate: • 86.121%* • *from an SRS of 19 from 194 countries

11. Literacy Rate T-test Conditions: State SRS Pop ≥ 10n Normal Pop or n ≥ 30 Check Assume Representative There are more than 190 countries Assume distribution of all literacy rates in the world is normal

12. Literacy Rate T-test P(t<-2.8314│df=18)=.0055 We reject the Ho because the p-value of .0055 < α=.05. We have sufficient evidence that the true average literacy in the sampled countries is less than that of the U.S.

13. Age Structure Data 167 22 11

14. Comparison of Age Structure Conclusion: the age structure of the entire Philadelphia population roughly matches the age structure of the World

15. GOF of Age Structure The distribution of age fits the expected distribution The observed H distribution does not fit the expected distribution Conditions: Check Age groups are categorical Assume Representative All expected counts ≥ 5 State Categorical data SRS All expected counts are ≥ 5

16. GOF of Age Structure P(x2 >31.0562│df=2)=1.804x10-7 • We reject the Ho because the p-value of 1.804x10-7 < α=.05. We have sufficient evidence that the distribution of age for Philadelphia does not fit the distribution of age for the world.

17. Philly’s Gear-1 Prop Z-test • 9 out of the 200 people observed were wearing Philly’s gear Conditions: Check Assume Representative (200)(.2)= 40 ≥ 10 (200)(.8)= 160 ≥ 10 3. There are more than 2,000 people in Philadelphia State SRS np ≥ 10 nq ≥ 10 3. Pop ≥ 10n

18. Philly’s Gear-1 Prop Z-test P(Z<-5.4801│df=199)=2.1309x10-8 We reject the Ho because the p-value of 2.1309x10-8< α=.05. We have sufficient evidence that the true proportion of people who wear Philly’s gear in Philadelphia is less than 20 percent.

19. OverallConclusions • The Philadelphia population matches the “Most Typical Person” in terms of age (middle aged), but not in terms of race • Will probably see changes in population makeup • The ethnicity of the entire Philadelphia population matches the ethnicity distribution of the U.S.

20. OverallConclusions Cont. • The age structure of the entire Philadelphia population matches the age structure of the world population • Literacy in the world is less than that of the U.S. • Average world rate lowered by underdeveloped countries • Less than 20% of the Philadelphia population sports Philly’s gear on a given Tuesday afternoon • Not much spirit?! Project Opinions • We found this project to be interesting in terms of: • Relevance to the world • Application of statistics skills to real data

21. Sources of Bias and Error • Some of our data comes from the internet so it may not be completely reliable • Censuses do not account for every single person and must be assumed representative of the population • Undercoverage • Only people who walked past us had a chance of being counted • We only went to three places • Doesn’t necessarily account for the • whole Philadelphia population