By Dale Denwalt Capitol Bureau ddenwalt@oklahoman.comAs Oklahoma prepares to collect taxes on marijuana, a new study from the Pew Charitable Trusts urges caution when relying too much on that money. The report released Thursday highlights the history of "sin taxes," or revenue collected from things like marijuana, gambling, tobacco and alcohol. "Sin taxes can provide short-term revenue boosts, but because of a combination of factors, they may also drive budget challenges in the long term," said Mary Murphy, project director for Pew's state fiscal policy division.Read more on NewsOK.com