Demographic Data PDF

Population and Society Prof. Childs 3.1 Demographic Data Main Sources of Demographic Data Sources of Error Census, Vital Registration, Sample Survey Coverage Errors Reproduc...

Population and Society Prof. Childs 3.1 Demographic Data Main Sources of Demographic Data Sources of Error Census, Vital Registration, Sample Survey Coverage Errors Reproductive History Survey (Beall and Leslie) Content Errors National Census: History Early censuses: Babylon (3800 BCE), China (3000 BCE), Egypt (2500 BCE), Rome (100 BCE). Sweden conducted its first census in 1749, the US in 1790, England in 1801. European precursors estimated population size - count houses, multiply by average household size (a guess). Arthur Young (1741–1820) Early advocate for precise and regular census (every five years). “At present we are very much in the dark on this head; our numbers are guessed every day; but from such imperfect authority, and with such great variations, that no sure dependence is to be placed in such random ideas.” Wanted not just numbers, but composition as well. o Profession: shopkeeper, laborer, farmer, merchant... o Socioeconomic status: landlord, vagrant, etc. Wanted results disseminated (publication of the tables of population) for government and public use. Original Census Purposes Government Revenue and Military Conscription US Census Constitutionally mandated. US Constitution: Article 1, Section 2 Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers... The actual Enumeration shall be made within three Years after the first Meeting of the Congress of the United States, and within every subsequent Term of ten Years, in such Manner as they shall by Law direct. Complete enumeration of the population. Conducted every 10 years since 1790. Questions and categories change according to perceived needs. Past: paid census enumerators tracked down people and asked the questions. Present: form mailed to every HH, fill in by self. Exceptions: non-compliance, difficult to enumerate populations (e.g., homeless). 2020 – first time online option available. Legal basis to make it compulsory. Penalty up to $100 for each question not answered; $500 for a false answer. Legal provisions to protect data confidentiality. A Distinction US Census Every 10 years; full enumeration. American Community Survey (ACS) Every year; sample of population. More details: jobs and occupations, educational attainment, veteran status, own or rent homes, etc. What Can Demographers Do with Census Data? Size and Distribution of the Population, Age-Sex Composition, Changes Since Last Census, Population growth/decline, Population aging, Cross-Tabulations by Characteristics (race/ethnicity, occupation).  What Can Politicians Do with Census Data? Gerrymander congressional districts. Redrawing of congressional district boundaries occurs after each census. Party in state power gets to redraw districts. In 1812, Governor Gerry (Mass.) signed a bill into law that redistricted his state to overwhelmingly benefit his party. One of the congressional districts was shaped like a salamander. “No it isn’t”, said one Federalist, “it’s a Gerrymander.” Vital Statistic Registers Recording of each individual’s vital events. Generally, birth, death, and marriage. Started as parish records, now kept by govts. Main purposes are administrative. Legal identification of people (try to get a social security card, passport, etc. without birth certificate!) Problems and Limitations: Until recently very few places had them. Very expensive to maintain. Tend to under- enumerate marginal groups who have less contact with bureaucracy (minorities; poor people; rural dwellers). Applications: Calculate birth, death, and marriage rates. Analyze patterns (e.g., age-specific fertility/mortality). Reproductive History Survey (Beall & Leslie) Critics “the collection of pregnancy or birth histories is no guarantee of higher-quality data than could have been obtained from alternative and less expensive survey strategies.” (Cleland). Time consuming to get the data (single interview can take over one hour). Need decent sample size (200-300) for analysis. Data Reliability Relationship with community? Long-term commitment? Local research assistants? Cross-Checking: ask another person to verify. Consult written records (natal horoscope). Sources of Errors (Surveys, Censuses, etc.) Errors of Content Enumerator writes down the wrong answer. Enumerator makes up the answer. Respondent does not understand the question and answers incorrectly. Respondent does not know the answer but still answers. Respondent makes up an answer in order to look better in the eyes of the interviewer (deference effect; social desirability bias). Respondent is reluctant to answer and lies. Example: China’s Missing Children (Goodkind) 2000 census: an estimated 37m kids unreported. o 1/4th of all children aged 0-4. 1/8th of all children aged 5-9 Why the Undercount? China’s Birth Control Policy: many exceed quota, reluctant to reveal “excess” kids to census enumerators. Local officials responsible (upon penalty of demotion) for ensuring birth quota compliance. o OPTIONS. Force constituents to conform; punish transgressors. Don’t force constituents to conform; be demoted. Obscure or underreport birth statistics. Errors of Coverage Under-enumeration. Surveyors either miss some people, or some people avoid surveyors.