We Obsess With Precision When Trends Are What Matter

I had my annual physical last week. Because of family history of heart issues, I take my blood pressure on a regular basis.  I reported my home readings to my doctor. 

Of course, the first test when I walked in the room was taking my blood pressure.  It was high.  The doctor and nurse said they would retake it at the end of the exam.  After my exam ended, they put me in “time out” for 10 minutes.  I had to sit and relax by myself.  I kept my phone in another room.  Ten minutes later, my blood pressure was “excellent.”  My doctor explained that the 120/80 blood pressure that is now considered normal was taken from a study where people sat for 10 to 20 minutes prior to the blood pressure being taken.  I wonder if the companies that sell blood pressure medication talk about that part of the study’s protocol. 

From an early age, we are bombarded with the importance of precision.  There is one correct answer on a test.  Questions we are asked require yes or no answers. We applaud scientists and pseudo-scientists (economists) for giving us precise numbers on topics that are difficult to understand like climate change and economic growth.  We stand in awe of their confidence when they report numbers that have decimal points to us. 

Trends can get lost in our quest for specific, precise answers.  Isn’t it more important for my health to measure my blood pressure over time than once a year at a physical?  Isn’t it more important to focus on the trend for the economy than a quarterly number that is reported out 3 decimal points?  Can anyone, let alone the government, provide a real GDP growth number that is that precise?   

Over these next several weeks, we are going to be inundated with facts and figures about the economy and about coronavirus.  You will be better served focusing on trends rather than specific numbers.  Anyone who reports a specific number with confidence to you has an agenda.

Comments are closed.