Department of Awful Statistics: Why Ask Y?

It is that time of year again: the time when advocacy groups produce graphs with Y-axes that start at some arbitrary number in order to make their issue look bigger.  Consider this heart-rending graph from the Working Poor Families Project (via Felix Salmon):


working.jpg

Why does the graph bottom out at 25, you may ask.  Why indeed? This is what it looks like when it starts at the more traditional number of zero:


Working Families2.png

It looks like the percentage actually doesn't change that much, moving up slightly in recessions, and down slightly in good times.  We see that now, in a remarkably deep recession, it gets a little worse.  But not surprisingly so.  In the top graph, the changes look approximately five times bigger than they are.


This is not to downplay the problems of poverty and near-poverty, which are a discussion for another day (but for which I'm not sure 200% of the poverty line is a particularly useful measure).  It's simply to point out that things can look very different depending on where you start the Y axis.  And in my experience, as advocacy groups launch into their end-of-year fundraising season, Y axes seem to creep closer and closer to the bottom value in the series.
Presented by

Megan McArdle is a columnist at Bloomberg View and a former senior editor at The Atlantic. Her new book is The Up Side of Down.

Riding Unicycles in a Cave

"If you fall down and break your leg, there's no way out."

Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register.

blog comments powered by Disqus

Video

Riding Unicycles in a Cave

"If you fall down and break your leg, there's no way out."

Video

Carrot: A Pitch-Perfect Satire of Tech

"It's not just a vegetable. It's what a vegetable should be."

Video

An Ingenious 360-Degree Time-Lapse

Watch the world become a cartoonishly small playground

Video

The Benefits of Living Alone on a Mountain

"You really have to love solitary time by yourself."

Video

The Rise of the Cat Tattoo

How a Brooklyn tattoo artist popularized the "cattoo"

More in Business

Just In