From Theory to Evidence

1. From Theory to Evidence 22 February

2. Hypothesis vs. Research Question • When no expected direction to relationship. • Exploratory research, not deductive

3. Elements in Hypotheses • Variables • characteristics of the units we are studying • Theoretical population • Units of Analysis • What the variables are characteristics of: individuals or a larger unit [e.g. states, countries] • Direction of relationship

4. Concepts • Democracy, power, representation, justice, equality, trust, social capital • Many interesting concepts are abstract and lack a completely precise meaning • One strategy is to defining concepts by being explicit • Express a concept in a form that is observable and includes some notion or degree of differentiation • This process is called operationalization

5. What is a variable? • Interesting questions in social science center on concepts that involve variation and how changes in one phenomenon help to explain variation in another • Process of Operationalizing Concepts • Democracy could be defined as having certain attributes • Ie. Number of parties • Political Engagement as another example • Forms of political participation

6. Measurement • Are these measures any good? • Reliability • Validity

7. Types of Variables • Dependent • Phenomenon trying to explain • Independent • The variable you are using to explain variation in the phenomenon • Dependent  independent • The value of the dependent variable depends on the value of the independent variable

8. Units of Analysis • Along with proposing a relationship, a hypothesis also specifies the types or levels of political actor to which the hypothesis is thought to apply • Individuals, groups, cities, countries • Problems with mixing different levels of analysis • Ecological fallacy • Using information that shows a relationship for groups to infer that there is the same relationship for individuals

9. Direction/Nature of Relationship • Positive – as one variable increases the other also increases • Negative – as one variable increases the other decreases • As age increases, probability of voting increases (+) • As political cynicism increases, probability of voting decreases. (-)

10. Prob of Voting Age Prob of Voting Cynicism

11. Problems in Formulating Hypotheses • Vague or trivial prediction • Vague relationship • Value statement • Deals with a case and is not generalizable [theoretical population should not be one]

12. Problem Hypotheses? "Ronald Reagan was a stronger president than Jimmy Carter." "The number of convicts on death row is greater in Texas than in Utah." "Republican electoral success is related to how the economy is doing." "Americans are generally satisfied with their congressional representative." "People who are dissatisfied with the government tend to exhibit political cynicism." "More legislation was passed by Congress in 1934 than in 1954." "Corruption among world leaders is related to average annual rainfall in their country's capital." "Political participation is high among residents of affluent suburbs."

13. Variables, units of analysis and direction of relationship: "The greater the inequality in the ownership of land in countries, the greater the civil strife." "Women are more likely to oppose capital punishment than men." "Local television news stories are more likely to be about crime than network news stories." "The proportion of the vote a party receives determines the proportion of seats it receives in the legislature." "Daughters tend to acquire their interest in politics from their mothers." "The greater the number of highway patrol officers per capita in a state, the fewer the number of highway fatalities." “Interest groups that spend the most on professional lobbyists receive the greatest financial rewards from government programs." "The size of a government agency influences the decision-making authority of its director." "Lawyers who attended highly rated law schools are less likely to run for elective office than those who attended less prestigious law schools."

14. Types of Relationships • Null hypothesis • Correlation/association • Causal • Spurious

15. Spurious Relationship • a relationship in which two variables that are not causally linked appear to be so because a third variables in influencing both of them

16. + # of fire trucks responding to call Fire damage in $ + + Intensity of fire Spurious Relationship

17. + Party quotas %women elected + + Political culture Spurious Relationship

18. Correlation/association vs. causation • Co-variation • Time • Consistent with other evidence • Rule out rival explanations