I want to talk about 3 popular market interventions that are meant to "help the little guy": minimum wage, collective bargaining, and rent control.
Many people feel "collective bargaining" is a not a market intervention, but I beg to differ -- when companies collude to fix prices, it is against the law and they can be prosecuted. Collective bargaining is when employees collude to fix prices. Allowing collusion by any actors in the marketplace is a form of market intervention.
When an employee is hired for a market-value wage, the employer knows that it will not be trivially easy to replace them. Thus, the employer fears their employees leaving and tries to keep them happy.
Imposing a minimum wage raises wages, but because the wage is above its market value, there wind up being fewer jobs than applicants. In that context, it is trivially easy for the employer to replace the employee, while a loss of the job is catastrophic for the employee, who may take a long time to find other work. As a result, the employees get treated like dirt, and they put up with it.
Allowing collective bargaining is different from imposing a minimum wage. It is similar in that it raises employee pay and wipes out the individual bargaining position of the employee. However, the union is in a position to watch out for them, and it becomes painfully clear to the employee that without the union, they are nothing to the employer. They don't realize that if they were being paid market wages, the employer would value them much more -- they become convinced that without the union, they would have no rights at all. Any criticism whatsoever of collective bargaining with such people sets them off raving about how collective bargaining is a basic human right guaranteed by the constitution, which is utter baloney.
Imposing rent control, similarly, means imposing a shortage of housing. At that point, it becomes harder for tenants to find a place to live, and easier for landlords to replace tenants. The relationship becomes skewed -- one actor, the landlord, finds himself in a position of complete power, while the tenant finds himself in a position of complete helplessness. This is greatly exacerbated by the fact that in most rent control schemes, if the tenant leaves and is replaced, the landlord can charge a higher rent to the new tenant. The tenant has negative bargaining power.
This creates a situation where the landlord has a large disincentive to make his tenants happy. He drags his feet about fixing anything. When I moved to NYC from a non rent-controlled area, I seemed to always be running into people who were suing their landlords, because the only way they could get their landlord to fix anything was by filing a lawsuit. Society winds up needing a byzantine set of laws about what landlords have to fix and when, while if everybody were just paying market rents, all these laws and lawsuits would be totally unnecessary, since landlords would be motivated to keep any decent tenant happy.
The consequence of this is that, in a rent-controlled context, renters really despise their landlords, and it becomes politically infeasible to allow rents to keep pace with inflation. In NYC 40 years ago, rents got so low that in many apartment buildings, the rent collected was less than what was required to maintain the building, and many landlords went Galt and abandoned them -- I've heard there were many abandoned tenements, especially in the South Bronx.