It's interesting to see that the average earnings of people who bike to work are increasing so much faster than the other groups. There's a stereotype that people who bike for transportation are just rich spoiled white liberals. I have no idea where it came from, and I'm pretty sure that historically it has been the opposite of the truth, but it's used as a political weapon by people on both ends of the political spectrum to argue against investments in bike-friendly infrastructure. People on the right stereotype cycling as a snotty badge of childless affluence and liberal virtue. On the left there's obviously a lot of support for bike infrastructure, but there are also public transit zealots who paint bike infrastructure as a perk that white gentrifiers award themselves, basically using the logic that public transit = diverse and good, cycling = rich and white and bad, therefore it's regressive to spend scarce alternative transit money on cycling.
The common thread on left and right is the assumption that biking as transportation is an activity of the affluent and educated. I've always wondered if a social stereotype that is so widely held across different groups in society can avoid becoming true. Maybe the rise of the average of wages of people who bike to work shows the stereotype taking effect by inducing more and more well-off people to see biking to work as an appropriate activity for someone like them.