This is a very good explanation, in language that should be clear to everyone, and I recommend that you send it to every newspaper in the US to print in their letters columns whenever the less informed begin holding forth. Nicely done and thanks.
To the extend that there’s places that offer more than massage, they stay open because the workers are independent operators leasing space from the owner rather than employees. If the cops do a sting operation and catch one of the workers offering happy endings, the worker is generally out of jail within a day while the owner is like "I had no idea one of the independent contractors leasing space from me was offering those types of services. If only I had known I would have had her evicted!
There was that study in Freakonomics that showed that in Chicago a prostitute was more likely to service a cop than be arrested. The agreement with the pimps was that they’d keep it discreet and away from the playground and provide occasional freebies to the police, and in turn and the police wouldn’t make much of an effort to make arrests of anyone involved. It wouldn’t surprise me if happy ending type massage places have a similar agreement with the local police.
One problem with stopping human trafficking is the definition. An undocumented live-in maid could result in human trafficking charges. In the massage parlors, legit or otherwise, if the workers live at the establishment, sometimes nothing more than a zoning violation, the owners can be charged with human trafficking and the workers disperse because they have to find work, and for various reasons the workers are reluctant to cooperate with authorities.
I’m not trying to minimize human trafficking in any way, but massage parlors are the low hanging fruit for the authorities, shutting them down does little to nothing about more serious human trafficking which will require far more law enforcement resources than are made available. And then it makes big headlines for a little while, some people even think something is being done about the problem, but very little is. As long as undocumented workers are more afraid of getting arrested and deported than they fear their employers it will be very difficult to change things. Then throw in drug addiction and runaways from abusive homes and the problem gets worse.
I don’t know what the solution is, but the same old same old is not working.
Is this opinion, or do you have cites?
I used to get deep massage therapy from a woman at my chiropractor’s office. It was anything but pleasurable, I can assure you.
Don’t confuse undocumented workers afraid of getting deported with slaves kept in line by watchful gangsters via violence, sexual abuse, and death threats.
As for why someone would register a skeevy brothel as a “massage parlour”, which is not exclusive to the United States, I would have automatically assumed it’s because they are operating in a state where prostitution is illegal and they can’t can’t go on the tax board’s books as a brothel. I expect some places advertise flower arranging or catering.
“I want a bouquet, you know, I wanna get my flowers really arranged real good. Do you sell the ones that come with …you know, lamb’s tongues?”
“Are you asking for floral sex?”
It’s a bit of a slippery slope, though. A sex worker may loathe what they do, yet still choose to do it as a way to escape misery and make a living. What I am trying to say is that there may not be someone compelling you, but unfavorable circumstances may. Free agency is expensive and a lot of people who do not have the means may not have the luxury of saying no to everything that they don’t want.
I’ve worked in call centers, there’s little I don’t know about the compulsion inherent in staying in a shitty job. When I say “compelled” I’m talking the difference between “Eh, it’s a living even if it sucks, gimme my paycheck” and “Since I’m barely healed from the last beating I guess I choose to suck this dude’s dick rather than get another beatdown.” I think we can agree there’s a shit ton of daylight between these two scenarios even if they both involve work one would prefer not to do.
Agreed, they are very different and in both cases the worker does not have real agency.
If I’m taking an alternate route to work, I will drive by about 15 massage parlors, and about 10 have the telltale signs of being a sexualized Asian massage parlor (seedy strip mall, sometimes around strip clubs or truck stops, usually not located in the Asian communities, open 24x7, has something vaguely “oriental” in the name, only has English signage, does not specialize in foot, hand, or face, sometimes shows an iconized palm tree represented in a rather… erect fashion.)
Honestly, I’m not doing a research paper here. I just notice that every few years there’s a big rash of busts and then they ignore it for a few more years because the cops are customers who are in on it (source, again: busts in the newspaper). But just going off curbside appearances it looks to me like a 2/3rd majority of “Asian massage parlors” are sexual businesses. It’s a well known fact that Georgia has let these run amok even while leaning heavily into “child predator” campaigns that feature images of scared-looking white girls. I expect this is about to change.
That doesn’t mean I condone any part of the situation. Just pointing out here that if we’re talking about Atlanta massage parlors, there’s a really good chance there’s some sexual involvement, and it’s not out of line to take it into consideration.
There’s also the middle ground of “you were brought here illegally and know no one and have been led to believe that any attempt to leave will lead to arrest and immediate deportation”.
Often, the “physical violence” standard is used to suggest that basically if there are no signs of a struggle, it wasn’t coerced.
Or merely be thrown out on the street in a strange land, or there will consequences against family members back home.
True, it is often tough to communicate the broad range of forms of coercion.
I do get it that SmartAleqpoints to there being a distinction between compelled by legitimate economic necessity, and coerced. “Eh, it’s a living even if it sucks, gimme my paycheck” is understood to be just part of how life is, as long as the call center worker or coal miner is paid per the law and is still free to quit and move away but does not only because there are no jobs waiting for them elsewhere, as opposed to someone actively preventing them. Physical violence is just the more extreme form of coercion.
As others have noted, massage therapy is a legitimate, non-sexual business in the U.S., and legitimate massage therapists are usually licensed at a state level.
However, I’m not sure that I’ve ever seen a legit massage therapy business that’s referred to as a “massage parlor” – that (probably more informal) term seems to primarily, if not exclusively, applied to places which offer “happy endings.”
Of course, and my examples were chosen intentionally to present the two extremes of a spectrum of coercion rather than to suggest there’s nothing in the middle of the two.
I hope she does not rub him the wrong way. 
Thailand has lots of “massage parlors,” but many people are surprised to learn there are many legitimate ones too. The local belief is that the blind make the best legitimate masseurs/masseuses. I knew a blind massage therapist back in university in Texas, and he was very much legitimate.
Does that local belief have to do with the history that some types of Asian massage, like Japanese 按摩, were during certain periods the exclusive preserve of blind practitioners?
I have never heard of it ever being the exclusive preserve of blind practitioners in Thailand. But I don’t know the origins of the local belief.
Because anti-sexwork laws are unconstitutional, but no lawmaker has the balls to challenge them. So, much like cannabis laws, they are more widely scoffed than obeyed.
In the metro Detroit the Thai massage places are generally legit spas that offer many techniques such as hot stone, back walking and Swedish massage. The ones marketed as Asian, Chinese or Heath spas are generally happy places. 
You can Google any major city for happy ending massage and find out fairly quickly where they are. These places haven’t been hiding, they just keep low profiles.