In the article, "BYU Study Finds PG-13 Rated Films Make The Most Money", Mary Richards reports on a BYU-student based study finding the difference in money making potential between a R-rated and PG-13 rated movie is about 40% more for the PG-13. The study also finds that the closer the PG-13 movie is to receiving a R-rating, the bigger the profits.
These findings, if proven correct, will motivate the movie producers to make the necessary changes in the final product to garner the PG-13 rating. However, producers will only cut out the least amount of content necessary to receive this rating to maximize the profits afforded to being as close to an R-rating as possible.
The result of the PG-13 movie demand curve shifting to the right is causing a forward shift in the supply curve from movie producers who are taking advantage of the shift in demand to produce higher profits and revenues. Also, because the profitability increases even more if the PG-13 movie increases in elements and material more like an R-rated movie, the differences in material between the PG-13 and R-rated movie will continually shrink.
The article stated that 55% of movies are R-rated and 35% PG-13. The percentage of PG-13 movies will increase in the future. Is this study conclusive evidence that movie makers should abandon making all R-rated movies? I do not think so. I assume that the movie industry will want to ensure the facts in the study are correct and that the findings are true due to the conservative nature of the school producing the results and other articles reviewing the same study but reporting different numbers.