The answer is no. Don't spank.
The trend, throughout the US, is away from corporal punishment, even if there is no trend to outlaw it explicitly. While spanking is not clearly outlawed in Massachusetts, our case law does not clearly condone it either. And there is currently proposed legislation here that would indeed explicitly outlaw it; if the legislation is passed, Massachusetts could become the first state to prohibit parents from using corporal punishment.
I just read an interesting post on the subject in today's Massachusetts Law Updates, the Massachusetts Trial Court Law Library's blog: Spanking and the Law. Although I'm not sure a law banning parents from spanking their children is necessary or even a good idea, I am sure myself that spanking itself is a bad idea. I believe parents should act as though such a law is already in effect.
I say don't spank, first of all, because as a parent I don't believe spanking is a good means of discipline, I have never used it myself, never needed it, and never would use it. (Of course, my current aversion to spanking may have something to do with the fact that my son is now old enough and big enough to spank me back...)
Second of all, I say don't spank, because I am a divorce and family law attorney. As such, my clients are by and large parents who are in the process of getting divorced, parents who are already divorced, or parents or other parental figures in divorce, guardianship or paternity disputes. Such parents in particular often have to worry about potential or ongoing disputes with other parents or other rivals in custody and visitation matters, and it's not generally a good idea to be giving your potential enemies ammunition to use against you.
But finally, and most importantly - and this is strongly related to my own personal objection to spanking - I say don't spank because there is a fine line between physical discipline and abuse. Where there are children, there are mandated reporters. In our schools and hospitals, and elsewhere, there are officials, teachers, counselors, medics, medical and psychological professionals, who are mandated to report any suspected neglect or abuse to the Department of Social Services.
Really, it's just better not to spank. There's a better way.
Massachusetts Law Updates: Spanking and the Law