The first case that comes immediately to mind is Range Resources, in Pittsburgh, which drilled shale gas wells in poorer neighborhoods because the residents wouldn't have the resources to pursue lawsuits against them (http://www.post-gazette.com/powersource/latest-oil-and-gas/2...). State and federal regulatory agencies help to level the playing field (when they aren't being corrupted -- but that's another matter). In the absence of effective regulation, poorer communities have no recourse against being exploited.

This isn't just happening in one specific location, either. There is a national correlation between poor communities and pollution: https://www.washingtonpost.com/news/energy-environment/wp/20...

Deregulation in 1996 was also a major contributing factor -- possibly the key factor -- that led to the California state energy crisis in 2000-2001 ([pdf] https://www.ferc.gov/industries/electric/indus-act/wec/enron...)

Here's a really interesting insider perspective on the intersection of economics and regulation: http://allegedwisdom.blogspot.com/2017/03/the-story-of-lucky... ... this guy estimates the "trans fats ban" saved a few tens of thousands of lives. The article also opens by describing a case in which proposed regulation would not have made sense, but don't stop there.

Under-regulation has maybe cost the United States 41 million IQ points: https://www.theatlantic.com/health/archive/2014/03/the-toxin... ... think about that the next time you wish the people around you were smarter.

And, while lack of regulations have over history cost this country an untold amount of money and lives, it's not at all clear that environmental regulations have a net negative impact on the economy: https://www.vox.com/science-and-health/2017/3/2/14772518/env...

As Cory Doctorow points out, modern software has changed the rules around regulation and cheating, and there are lots of incentives to cheat: http://locusmag.com/2017/09/cory-doctorow-demon-haunted-worl.... In cases like these, we're simply getting a glimpse at how the various actors involved would behave in a completely unregulated environment. Too many people now are too young to know first-hand what an unegulated country looked like: http://www.businessinsider.com/photos-america-before-epa-doc...

As the blog from the economist alludes to, there are bad regulations too. I'd be quick to agree with that. But while it's far too simplistic to merely say, "regulations are good" or "regulations are bad", it's not hard to find evidence that our lives are overall much better off with many of the regulations we have in place now.