The Logic of Scientific Causal Inference An Introduction to Designing Social Inquiry

Learning goals Overview of the class Overview of the paper for the class

Logic of Scientific Inquiry Inter-subjective Standards Mathematics Logic Subjective Standards Religion Normative philosophy

What is the job of a social scientist? To try to use whatever tools we have at our disposal to prove ourselves wrong. Tools: Logic Empirical observation Try to disprove our theory as much as possible Unfortunately, we cannot prove anything Always estimate the level of uncertainty in any claim There is always uncertainty; it is not a death knell

You need a dependent variable What causes ‘y’ to vary? The ‘y’ is your dependent variable The causes of y are your independent variables The variables must be measured along the same units, in this class, the units are people

Problems in social sciences, especially when studying people Bad theory Maybe it is something else, related to your cause that is doing the causing Maybe it is reverse causality Maybe there is something important that intervenes between the two variables Maybe the cause works in one condition but not another Bad measures Some aspects are not intersubjective

The Research Question: Why does ‘y’ vary? Why do some people vote for Democrats and others for Republicans? Why do some ethnic conflicts get resolved and other end in holocausts? Why do some democracies remain stable and others fall apart? Why are some economies successful and others are not? Why do some civil conflicts result in revolution and others do not? What causes some people to support the civil liberties of political enemies? What causes some people to trust one another and others not to trust? What causes some people to participate in their government? What causes some people to bring litigation against their government?

Measurement

Continuous v. Discrete Measurement Inter-subjective Measures Inches Degrees Fahrenheit Dollars Continuous v. Discrete

Concepts that are difficult to measure intersubjectively Democracy Self-Esteem Ideology

Face Validity: Political Tolerance Tolerance implies dislike. So, we do not ask Black Lives Matter activists whether they believe BLM activists should be allowed to march. So, you have to first ask who their worst political enemy is and then ask whether they should be allowed to march. If your worst political enemy (i.e. Nazi’s, KKK) came to your town, would you support their right to march downtown? Not support at all Not really support Somewhat support Strongly support 1 2 3 4

High Variance Mean

Low Variance Mean

Political tolerance as an example DV What causes some people to support civil liberties for those they dislike? Dependent variables must vary

Variance: Political Tolerance 40 35 30 Lowest 25 Low Number of People 20 Medium 15 High 10 Highest 5 Political Tolerance

Correlation is not causality Few Fire Trucks Many Fire Trucks Low Fire Damage 40 10 High Fire Damage Fire trucks  fire damage Storks  babies Few storks Many storks Low births 40 10 High births

We will be spending a good part of the class figuring out how to differentiate evidence of a cause versus other reasons for correlation

Observational study Survey research: what causes people to believe, perceive, value, or act Questions that measure the concepts that are your DV and IVs must be in the same survey Plot people who answer a question that is the dependent variable on the y axis Plot an independent variable on the x axis

The Literature Review You must, while developing your causal theories, find the relevant literature The goal is to go wide This means Find literature about your DV – what have others found Find literature about other DVs that are related to your DV Find literature about your IVs – what other concepts are related to your IVs

What causes people to be politically tolerant? 40 35 30 Lowest 25 Low 20 Medium 15 High 10 Highest 5 Political Tolerance

Correlation We attach values on one dimension to values on another For political tolerance, one common theory (and finding) is that education causes political tolerance Why would education cause political tolerance? Are there other variables, related to education that might also cause political tolerance?

Statistical Relationships 40 3 3 3 2 35 2 3 3 1 30 3 2 1 3 Education 3 1 25 1 3 3 3 1 Lowest Low Medium High Highest 3 3 20 2 2 2 3 2 4 3 2 2 3 2 4 3 15 2 1 4 3 4 2 1 2 3 4 3 4 3 2 2 3 2 4 5 10 1 1 2 3 4 3 4 5 5 4 4 1 1 2 2 3 3 5 5 5 5 5 1 2 2 2 3 3 4 4 5 5 2 1 3 2 3 4 3 5 5 4 5 1 1 2 3 3 3 5 4 5 5 1 2 3 4 5 Political Tolerance

Statistical Relationships 6 Slope 5 4 Political Tolerance Mean 3 2 1 1 2 3 4 5 6 Education

Probability: Best Guess What is the probable value of tolerance, given condition of education? This is what the slope tells us. 6 Slope 5 4 Political Tolerance 3 Mean 2 1 1 2 3 4 5 6 Education

Controlling for all possible causes This is not realistic, but this is the goal For something to cause something, it must, in a sense, come first If there is no time change in the research design, (and in our projects, there is not), then you must figure out other ways to capitalize on time variance You can use theories of life development to determine what came first Do not control for something that does not cause

Your project You should find about ten-twelve non-demographic concepts that cause your DV You have to find literature that helps establish that causality Be critical of that literature Identify something that is nonobvious Nonobviousness is related to falsifiability Be skeptical of your finding Figure out what it means that your nonobvious concept causes your DV