One way to do that might be: require the unions to carry settlement insurance. Require that insurance payments are made directly out of union dues. Increasing c

One way to do that might be: require the unions to carry settlement insurance. Require that insurance payments are made directly out of union dues. Increasing cost of insurance cost would act as a deterrent. Of course, that would be short-circuited if cities raise wages (paid by taxation) to cover those dues.