How many states have shot clocks
 

For high school, that is.

And which ones are they?

Not very many. ;)

Peace

According to a newspaper article I found, they are:

California
Massachusetts
Rhode Island
Maryland
New York
Washington
North Dakota
South Dakota (just started this year)

At last count the number was seven.

CA (both), WA (girls), MD (girls), ND (Class A), MA, NY (Long Island), VA (private school girls league in Northern VA), and a prep school league in New England.

http://forum.officiating.com/showthread.php?t=6565

The Land Of Steady Habits ...
 

Boys and girls varsity prep schools here in Connecticut. No shot clock for subvarsity games.

Missouri doesn't have the shot clock, but I've noticed that two new gyms this year have shot clocks installed above their backboards. I guess some of the newer baskets have shot clocks already attached to them? One of them had the shot clocks directly above the rim, but it stuck out an inch or two in front of the backboard. We had two shots hit one of the shot clocks.

Ri
 

RI
Boys :35sec. shot clock
Girls :30sec. shot clock/no :10 sec. count

Really? That's illegal in NCAA (the shot clock must be recessed), so I'm surprised that an installation would allow the clock to be installed in front of the plane of the backboard.

The hard thing about adding the shot clock to your state is that you forfit your seat on the Fed rules committee.

I didn't realize so few states had a shot clock. Being in a state (WA) that has one, for girls anyway.
I like a shot clock. It rewards good defense, and seems to prevent teams from "slowing it down" too much.
Does anyone know the rational for not having a shot clock?

States that had coaches/athletes that didn't care to 'slow it down'? ;)

1. Cost. Installing shot clocks in every gym in a state is not a cheap expense, especially when many schools are already strapped for cash.

2. No reason to do so. IMO, the shot clock is simply a tool designed to make the game more 'fan friendly,' but has little rationale outside that. Why should a team not be able to run an offense that works the clock?

It is more than just Long Island in New York. I called in the Albany area with shot clock. I know for a fact that girls use it across the entire state (started in 07-08 season for girls).

I am pretty sure NY (Boys) uses a shot clock everywhere - we certainly do in upstate.

In NY, the girls play under NCAAW rules (with some modifications) and have had a 30 second shot clock for at least 10 years. I don't do boys (who use Fed rules with some modifications), but I believe they do use a 35 second shot clock.