I'm not sure where there's more economic illiteracy: the DoJ or this forum...This is a fact borne out by the immeasurable damage that anti-trust laws have done to many U.S. industries (including, sadly, the film industry -- in the old studio system, there were 2000 movies made each year and 200 producers; in the post-anti-trust studio system, 200 movies are made each year by 2000 producers.."
I don't know where you are getting your stats for feature films but the numbers don't correlate with industry pubs.
Breaking up the three arms of production, distribution and exhibition was hated by the major moguls in Hollyweird as they no longer had a stranglehold on what could be offered to the viewing public. It was "go see what we put out or sit at home and listen to your radio" as my grandpa used to say.
If you are inclined to believe that feature film production is down due to this string of dismantling, then you might consider the factors in play at the market in contemporary culture. It's not my grandpa's or even my pops viewing audience these days. It's a whole new (younger demographic) world out there and has been for some time. There are also many many more films making much more money than before using much simpler technology. You may not like them, but then, a younger generation does.
Regarding the stats, it's not a hard number, but a ballpark range given by David Mamet in a book he wrote about the motion picture industry. Honestly, I wouldn't be surprised if the true numbers are even worse. John Ford, for example, made well over 100 films, the majority of which are excellent; the best directors today are lucky to make a dozen, despite lower costs through better technology. And no one should E-V-E-R trust studio-published figures (especially if you make movies for them!).
The three arms of production in the old Hollywood system were similar to the principles by which Apple operates and excels today: provide a great experience that builds brand value and trust. The differences between viewing a film at the extinct studio owned and operated movie palaces and contemporary AMC/Regal megaplexes is more dramatic than the difference between buying a mac at an Apple store and Wal-mart. The movie palaces were stunningly beautiful and had incredible service; contemporary theater chains have more in common with Big Lots.
Another huge problem introduced by the anti-trust regs: the rise of entertainment industry unions. They collude with the studios to bar entry to newcomers, thereby killing outside competition and artificially inflating their wages. The studios are happy to comply, as the result is to prohibit independent filmmakers/actors from working with unionized talent. You can only direct a studio film if you're in the DGA, and you can only register with the DGA if you've directed a studio film (with some rare exceptions). See the problem there?
Back when actors were on contracts -- like every other jerk working on the production, they made more movies per year and for far less pay. Illegal downloading isn't killing the industry: exorbitant, $20MM fees for actors are.
This is a pretty good article about the old studio system and anti-trust laws:
http://mises.org/freemarket_detail.aspx?control=178