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Showing posts with the label third variable problem

Bad credit scores as a predictor of dementia

NPR aired this story by Sarah Boden  about the relationship between risky financial behavior and dementia. It consists of Boden interviewing people caring for individuals with dementia and dementia researchers. Before the NPR story, Boden published a related piece to a Pittsburgh NPR station . The Pittsburgh piece is a more formal report with many links to helpful information. Among the research Boden describes is this study by Nicholas et al. (2020),  which finds that people exhibit poor financial decision-making up to six years before a dementia diagnosis. Here is a press release about the study, in case you want to give more advanced students a primer or earlier UG students a sheet for understanding the research.  The audio version of this story is very compelling. It includes interviews with several people who have been left heavily in debt because of poor decisions made by family members before their diagnosis. It also offers some solutions that could be implemented ...

Shapiro's "New Study Links Widening Income Gap With Life Expectancy"

This story is pretty easy to follow. Life expectancy varies by income level . The story becomes a good example for a statistics class because in the interview, the researcher describes a multivariate model. One in which multiple different independent variables (drug use, medical insurance, smoking, income, etc.) could be used to explain the disparity the exists in lifespan between people with different incomes. As such, this story could be used as an example of multivariate regression. And The Third Variable Problem. And why correlation isn't enough. In particular, this part of the interview (between interviewer Ari Shapiro and researcher Gary Burtless) refers to the underlying data as well as the Third Variable Problem as well as the amount to variability that can be assigned to the independent variables he lists). SHAPIRO: Why is this gap growing so quickly between life expectancy of rich and poor people? BURTLESS: We don't know. More affluent Americans tend to engage...

Oster's "Everybody Calm Down About Breastfeeding"

I just had a baby. Arthur Francis joined our family last week. Don't mind the IV line on his head, he is a happy, chubby little boy. Now, I am the mother of a new born and a toddler. And I have certainly been inundated by the formula versus breast feeding debate. In case you've missed out on this, the debate centers around piles and piles of data that indicate that breast fed babies enjoy a wealth of developmental outcomes denied to their formula fed peers. Which means there is a lot of pressure to breast feed (and some women feel a lot of guilt when they can't/do not want to breast feed). However, the data that supports breast feeding also finds that breast feeding is much more common among  educated, wealthy white women with high IQs. And being born to such a woman probably affords a wealth of socioeconomic advantages beyond simply breast milk. These issues, as well as mixed research findings, are reviewed in Emily Oster's "Everybody calm down about brea...

"Correlation is not causation", Parts 1 and 2

Jethro Waters, Dan Peterson, Ph.D., Laurie McCollough, and Luke Norton made a pair of animated videos ( 1 , 2 ) that explain why correlation does not equal causation and how we can perform lab research in order to determine if causal relationships exist. I like them a bunch. Specific points worth liking: -Illustrations of scatter plots for significant and non-significant relationships. Data does not support the old wive's tale that everyone goes a little crazy during full moons. -Explains the Third Variable problem. Simple, pretty illustration of the perennial correlation example of ice cream sales (X):death by drowning (Y) relationship, and the third variable, hot weather (Z) that drives the relationship. -In addition to discussing correlation =/= causation, the video makes suggestions for studying a correlational relationship via more rigorous research methods (here violent video games:violent behavior). Video games (X) influence aggression (Y) via the moderato...