Speaking as a fan/reader:

Because so much SF is reactive - to the present, as well as to the past - there's a lot more impetus to be at least somewhat aware of the canon (independent of the fact that most of what's stood the test of time to remain popular is still damn good writing). For example, Hardwired is decent enough on its own, but having read The Moon is a Harsh Mistress suddenly reveals a level of world history that's simply not present in the text of Hardwired itself.

This is very common in the genre, whether by design or osmosis; more common, I suspect, than in most others.

As much as I enjoy stories that can exist in a vacuum, it's almost impossible to attain this state.

Thus, as a SF reader, you're encouraged, directly and indirectly, to dig into the genre's history in a way that, to make a flippant example, readers of romance novels aren't. This means that more older works will be in print, to cater to folks discovering the genre.

This, I think, is fundamentally very different from the trend you've noticed in the auto industry - in that case, auto makers are tapping into a long-gone passion folks once had for their cars - you'll notice that the models being revived are either the classic muscle cars, or ones that had an acute emotional or social reaction. Nobody is clamoring for a 2008 Reliant or Chevette.

Detroit automakers, much like Hollywood producers, are strip-mining the fertile past to make up for a grotesque lack of fresh creativity within their ranks - witness the chain of remakes of movies that were JUST FINE THE FIRST TIME, THANKS (I'M LOOKING AT YOU, SANDLER, AND THAT GODDAMNED TRAVESTY YOU MADE THE LONGEST YARD INTO...) *ahem*

SF, on the other hand, continues to come up with new and exciting stuff to build on the legacy of the past, or offer a new take on old ideas, or challenge them, or turn them on their ear.

I have nothing to add to your grid, but I did have a thought (which partially echoes what etcet had to say).

Unlike most products, doesn't bookselling compete not only with its current releases but, in effect, with all of the books ever written in the past? Not just used books, but look at all the written-long-ago titles in their umpteenth edition on the new shelves. Books that have been popular for years right next to Mainspring. So, your literary offspring are competing not only with those of today's other writers, but also yesterday's writers. Isn't that a bit daunting?

I'm trying to think of other products that are similarly sold. (Not vintage or used, but new.) What else besides the written word is like this?

Music and movies, I suppose. Classic DVDs are alongside new ones at retail and rental locations.

But outside the entertainment sector, the housing market is the only other place I can think of where existing/used inventory competes on an equal footing with novel inventory.

Well, that and politics.

How silly of me -- of course I knew that audio and video recordings fit in the same arena.

The housing sector is an interesting observation -- I would not have thought of that.

Perversely, there are some situations where an older home has an additional intrinsic value to some buyers merely by dint of its age, even if the buildings themselves are fundamentally similar (example: the friend who induced me to move into my present location, my house's 1918 build predating hers (1925) is a source of great annoyance to her, because not only is she into period restoration (arts & crafts style), but I'm very consciously *not*)

I imagine an e-mail to Charles Brown would result in that grid being filled out in practically no time at all.

Good point. I may drop a query to Locus later today as time permits.

Thanks!