Saturday, February 13, 2016

Can Science or Evidence Change Your Mind?

I was recently listening to an EconTalk podcast with Russ Roberts and Adam Ozimek, about why economists change their minds or don't and the impact or role of evidence.  In general it is hard to find good examples of people changing their minds about ideologically firm beliefs in the face of strong contradicting evidence.  Outside of the specifics of issues related to microeconomic theory (like the impacts of minimum wages on unemployment) or macroeconomics (are fiscal stimulus policies effective?) one example of a couple a couple of fairly well known people that have changed their minds in this regard include Mark Lynas and Bill Nye the Science Guy.

"There is an equivalent level of scientific consensus on both issues, I realized, that climate change is real and genetically modified foods are safe. I could not defend the expert consensus on one issue while opposing it on the other." - Mark Lynas, How I Got Converted to GMO Food, NYT April 24,2015 

“I went to Monsanto,” Nye said, “and I spent a lot of time with the scientists there, and I have revised my outlook, and I’m very excited about telling the world. When you’re in love, you want to tell the world.” - Proof he’s the Science Guy: Bill Nye is changing his mind about GMOs by Washington Post March 3, 2015 

On a personal note, rather than change my mind about issues related to economics/markets/prices I find that the evidence has made me less dogmatic, and more skeptical or borderline agnostic. Despite Leamer's influence, and the credibility revolution, I find issues like what Andrew Gelman refers to as the garden of forking paths and researcher degrees of freedom  weigh pretty heavily on my mind, no matter how solid the identification strategy or methodology as presented in a polished 'study' or paper.  

1 comment:

  1. Good points, Matt. I think there's another issue here. If the subject of discussion has a clear moral component (and they all do), then there are two levels at which "the evidence" can change our minds. I might believe that small change in the minimum wage doesn't affect employment (leaving aside the other margins on which a higher price floor might affect people's lives), I still might oppose it because I oppose 3rd party intervention in voluntary contracts on *moral* grounds.