Denmark, Finland, Iceland, Norway and Sweden. None of these nations have an minimim hourly wage enshrined in law. Instead many of the base terms of employment, including wages, are decided via collective bargaining between sector trade unions and representatives of public sector and business interest organizations.
I live in Sweden by the way, so feel free to ask me questions on the topic and I’ll do my best to answer.
My understanding of the research is that a higher minimum wage can increase costs, but as a lesser proportion than the increase (edit; to the wage). Labor costs are only portion of expenses for any business, and workers making minimum wage only reflect a portion of the workforce. So, there’s not a zero effect, but I believe it’s usually less than fear mongering would suggest.
I haven’t read into this in at least five years, so happy to admit my own incorrectness if someone knows better.