Chapter 4 Demographic Data

Chapter Outline Sources Of Demographic Data Population Censuses Registration Of Vital Events Combining The Census And Vital Statistics Administrative Data

Chapter Outline Sample Surveys Historical Sources Demographic Uses Of Geographic Information Systems Where Can You Go For Information? Who Uses Population Data?

Sources of Demographic Data Census of population population, demographic structure and characteristics. Registration of vital statistics population processes of births and deaths Administrative data Local population changes, geographic mobility and migration

Population Census U.S.: Censuses have been taken every 10 years since Canada: Censuses have been taken every 10 years since 1851 and every 5 years since Mexico: Censuses have been taken every 10 years since 1900, and every 5 years since 1990.

Populations in the Census de facto population - people who are in a given territory on census day de jure population - people who legally “belong” to a given area, regardless of whether they were there on the day of the census people included in the census on the basis of usual residence - roughly defined as the place where a person usually sleeps

Census Errors: Nonsampling Coverage error People who are missed or who are counted more than once. Content Error Problems with the accuracy of the data obtained in the census. Includes nonresponses to particular questions on the census or inaccurate responses if people do not understand the question.

Sampling Errors If any data in a census are collected on a sample basis, sampling error is introduced in the results. Sampling error is readily measured based on the mathematics of probability. Samples can be designed to ensure comparable levels of error across groups.

Difficulties Using Data Data collected in the census, by the vital statistics registration system, or derived from administrative records: 1. Usually collected for purposes other than demographic analysis and do not reflect the theoretical concerns of demography. 2. Collected by many different people using different methods and may be prone to numerous kinds of error.

Sample surveys  Used frequently to gather demographic data.  Provide less extensive geographic coverage than a census or system of vital registration.

Geographic Hierarchy of Census Data 1.United States 2.Region (4) 3.Division (9) 4.State (50) 5.County 6.County Subdivision 7. Place 8. Census Tract/Block Numbering 9. Block Group 10. Census Block

Geographic Information Systems (GIS) Computer-based system that brings maps together with data in innovative ways. Geo-referencing data to places on the map means different types of data can be combined for the same place, and for more than one time. Increases the ability to visualize and analyze demographic changes over time and space.