129 karma · joined August 15, 2011
Beyond that, I only have data on about ~2,000 movies that had sufficient critical/user reviews to include in the analysis.
With those qualifiers aside, here are a few data points. The scores are listed as critic/user:
* Columbia Pictures, acquired by Sony in 1989. Before 84/79, after 54/62. * Miramax Films, acquired by Disney in 1993. Before 89/87, after 76/74. * New Line Cinema, acquired by Turner in 1993 then merged with Time Warner in 1996. Before 68/82, after 47/65. * Paramount Pictures, acquired by Viacom in 1993. Before 80/78, after 64/62.
Just to call out a bias in the data, ratings for all movies decline over time (probably because every recent movie -- good or bad -- appears on RT). The average rating for movies released 1996 or earlier is 72/70, and after 57/64. Nevertheless, all of the above-mentioned studios (with the exception of Miramax) showed a meaningfully greater decline.