I imagine it's not an easy thing to analyze and quantify efficiently. But I will offer my own anecdotal evidence, sorry for the wall o' text:

Baltimore City resident, we have a typical urban dirtbike problem, recent seizures have had a positive impact but it's been a mess - people plural killed in hit-and-runs. Official policy? Do not pursue. Because they'll run, and kill and/or be killed in the process. Okay. Plan B? Nothing, basically, until this recent success in seizures, and the gangs still roam (cops also routinely seize illegal handguns and drugs from the same people). So those with the nerve to run from the cops and break a dozen laws in the process were given a free pass, is how that went. Proposals to build them a closed motorcross park with taxpayer money didn't get much traction, thankfully, and pun intended.

So a couple years ago I was riding home from my tax-paying job, uphill, in the rain, on my 49cc scooter (for those who don't know bikes, it's basically a coffee grinder motor and a headlight), at a blistering ~23mph. No tags, but a recent change in law says I now need them. I get pulled over. My reward for not leading the cops on a low-speed chase? A $300 ticket. I attempt to register with the MVA/DMV, and their website roadblocks me. I call them, they say the glitch is on their end, and they resolve it. So my lack of registration was at least as much their fault as mine.

Off to traffic court I go, fuck this.

That morning I'm the only person in a shirt and tie, every other defendant is wearing literally pajamas. Their cops don't show, and they're granted immediate release under FTA. My cop doesn't show, and I'm told to wait in the back of the courtroom until he does. When he does, I state my case, provide screenshots of the MVA website's glitch resulting in my inability to register the vehicle. The judge knocks off $100 but gives me 18 months probation. Probation, on a 49cc scooter. The thing wouldn't break the speed limit if I pushed it out of an airplane.

TL/DR plus bonus material: White boy gets the book thrown at him by a white cop and white judge while every related black defendant skates, and while leaving court to pay my ticket a black courtroom staffer says, "That's bullshit, they should've given you FTA when that cop didn't show." Funny how things play out, versus the narrative.