Historically speaking, in the US, unions were formed to protect workers from unfair and unsafe business practices and to create job and wage security. However, this was a time when most states and the Federal Government did not have labor laws or other measures in place to protect the employee.
As the years went by and the state and federal labor laws became more effective, the need for unions has waned considerably. A good example is the US auto industry. Unions were so effective at developing high wages and great benefits for its members, the auto industry nearly collapsed a few years ago trying to pay those wages and benefits. Billions in bailouts were given to the auto industry in order to prevent the collapse.
So, how would collective bargaining impact the food service industry? Higher wages? Health and retirement benefits? Safer and better working conditions? Job security? All of the above? Someone has to pay for that, right? Unlike the auto industry, the profit margins in the food industry are 10-15% on a great day. Once those profit margins disappear, the business folds and there won't be any government bailout money to save the industry. Its simple math really.
The real questions that very few employees think to ask and even fewer still know the answers to are: a) can the restaurant accommodate such an increase in overhead?; and b) if yes, how?
The first answer is by transferring some of the increase in overhead to the consumer. But, that will not resolve the problem in its entirety. After all, customers are willing to only pay so much for a plate of pasta.
However, the bulk of the increase in overhead would have to be covered through changes in labor costs which typically represents the largest percentage of any restaurant's overhead. An increase in employee compensation across the board means fewer employees. That means layoffs. The employees that remain will be required to take up the slack. That also means fewer hours. So, those that remain will be required to do more and do it in fewer hours. Try to imagine how that would play out in a busy commercial kitchen.
Then there is the impact it would have on the FOH, especially wait staff. Currently, tips make up quite a bit of a server's salary. Those tips tend to disappear when the public knows the server is making a substantial hourly wage. Servers in Seattle are learning this reality with great pain. This also means the servers can no longer decide how much of their income they report to the IRS. That means more in taxes. The net result is less money per month despite the fact they are making more per hour.
As an owner, we deal in staffing not so much as having enough people to do the work. Instead, we look at it as "how much will it cost per shift to get the work done." If I am forced to make that choice in my restaurant, I am always going to favor the FOH. Why? Because that is where the metal meets the meat. In the restaurant business, if guests are not being waiting on or tended to, they leave and do not come back. Therefore, I am going to make sure the FOH is properly staffed and if that means the line cooks have to take turns doubling as dish washers and the chef has to work the line during rush, so be it.
Then there is the issue of wage scaling. For example, let's say the executive chef earns a salary of $45,000 per year plus retirement and medical. Suddenly, the union came along and now the line cook is making 45,000/year plus retirement and medical. What should the executive chef's salary be now? $80,000/year plus benefits? The cost of providing such salaries is far beyond the reach of the average restaurant. Perhaps maybe in large hotels, large corporate restaurant chains or cruise ships. But, definitely not in privately owned restaurants. The profit margins are just not there. If the profit margins were 40% like they are in retail, unions would've probably happened a long time ago.