Did 'listening to recorded music' include radio? Does 'watching prerecorded movies' include TV movies? How much time was spent watching TV? Aren't TV audience trending down? Might some of this be displacement by DVD?

An analysis of revenue and units of DVDs would be very helpful - Figure 6 looks like a classic succession curve, as seen with other technologies such as fuel sources, though with a shorter time span. Adding DVD sales, pre-recorded and blank VHS sales and recordable CD sales to it would be illuminating.

By citing the listening/viewing statistics, you are missing 2 behavioural points. Music is listened to repeatedly; Movies less so. There should be a discount rate applied for this.

Secondly, the library/collector model has shifted too. Watching my friends and colleagues, the same people who used to buy huge home audio systems and collect CDs, are now buying huge home Theater systems and collecting DVDs. The amount of time spent viewing or listening to them may not increase, but what they are collecting has. In addition, collecting classic TV series on DVD is a growing market. An examination of retail space devoted to each makes this fairly obvious to the layman, but studying this empirically would be worth doing to test the hypothesis.

p21:

Of course, copying using cassettes requires having an original handy.
That means either borrowing one or purchasing a legitimate copy. The difficulty of borrowing might have been sufficiently great that most copies would have been made from originals purchased by that individual.

Not necessarily. I remember in my youth carefully recording songs from the radio to cassette by listening to the chart countdown, when the order was approximately known. I'm sure many people were transferring older vinyl to cassette as well for portability and making 'mix tapes'.

The succession from vinyl to tape was based on flexibility - portability, as you say, but also the ability to make 'mix tapes' - music sequenced by the customer, not the label. This could be done with singles, by a jukebox, or stacking changer deck, but cassettes let these juxtapositions be recorded for others, as memorialized in the book (and film) High Fidelity.

The succession from vinyl/tape to CD was based on Quality as well as portability. With recordable CDs we now have both.

With MP3 players such the iPod our existing CDs become far more portable. Being able to carry hundreds of albums in my pocket means I am far more likely to listen to what I already have, as it will do shuffle play across my entire collection, or let me pick out one song from a thousand in short order. I think once you get over the ability to carry it all with you, you do want to buy more, as you are listening to more music, but listening to much less music radio, as I have a bigger playlist than they do, and I like all the songs on it.