Is there a term for this economic concept?

I’m looking for a term for a product which is essentially immune to pricing pressure because it is attached to another product which has a much higher price. The specific example I was thinking of was college textbooks. The textbook purchases are mandated by the courses. And while you might base your decision on which courses to take by their cost, once you’ve committed to paying $10,000 in tuition you’re not going to quibble over whether the textbooks cost $100 or $500. So textbook companies are essentially free to overcharge for textbooks.

Is there a general term for this?

Maybe a Coercive Monopoly. But companies aren’t “free” to overcharge for their textbooks. I believe professors have a choice of what text they want to teach out of, and many of them (the nice ones at least) consider the price of the text before assigning it to a course. There are probably 100 different macroeconomics textbooks that could be picked from, so there is still some price competition going on, just not at the student’s end.

You might have a bad example there, since textbook publishers run on thin margins and are definitely NOT overcharging in the sense you are suggesting. Furthermore, students are responsive to even small differences in price, which is particularly noticeable in the used book market.

In any event, price inelasticity is the only economics term I can think of to describe something where demand remains relatively constant as price changes.

There’s no special term that I know of for one that is inelastic because of an association with a more expensive product… but I’m not sure the relationship you describe exists.

USB cables might be a better example. Most USB cables in a retail storefront are massively marked up. You really don’t need them unless you are buying a USB peripheral that needs it.

14’ usb cables can be had for a few dollars each, yet many retailers sell them for $20-$30 each.

I think it’s very unlikely that there’s any realistic pressure driving down prices when the people making the decisions aren’t paying those prices. The actual prices of textbooks supports this belief.

To get away from the specific example of textbooks, let me define the situation in general terms:

Say you have a choice between various products: A1, B1, C1, etc. Each product has seperately sold support products associated with it: A2, B2, C2, etc. If you buy A1 you will also have to buy A2 and so on.

Now let’s say the price differences between the various #1 products are at least equal to X. And the cost of any of the #2 products is less than X. So if A1 is the cheapest product, then whatever the cost of A2 is, it will have no real effect on A1’s relative cost: if A1 is less than B1, then A1+A2 will be less than B1+B2.

captive audience?

Not quite because the consumers have a genuine choice between A1, B1, C1, etc.

It’s a special case of an aftermarket.

The traditional examples of aftermarket transactions are copy machines and toner cartridges (where you purchase a copier and are then locked into the type of toner it uses) and those fancy little coffee makers that use discs of coffee to make single cups, like the Tassimo. Both are characterized by a fairly high fixed cost (buying the copier or the coffee machine) that reduce the incentive to switch.

Usually an aftermarket is a form of market segmentation where you draw a consumer in and then rely on him for a continued revenue stream - another good example is that some copier makers provide service for their copiers (there was an antitrust case about this a few years ago).

This doesn’t follow the standard definition exactly because the individual colleges aren’t always the producers of the textbooks. I will point out, though, that many large colleges do run academic presses, and that there’s speculation about collusion between educators and publishers.

I’m not sure whether there’s a specific term for aftermarket-with-collusion.

As a college teacher, I find that very hard to believe.

Aftermarket & lock-in are the critical ideas to the OP’s question.

But the pricing of accessories is not really immune to pricing pressure. It’s just resistant to pricing pressure at low levels compare to the price of the main product.

As an example, with new inkjet printers selling for $100, there may not be pricing pressure on ink cartridges between $5 & $10, but there sure is between $40 and $80.

Also, as long as competitve choices for aftermarket accessories exist, then they are subject to normal pricing presure.

E.g. Once I buy an HP printer I’m locked into HP ink catridges. Epson ink cartridges do not provide pricing competition against the HP cartridges (until the price distortions get huge).

But used refilled HP catridges do provide competition to new HP cartridges. As would some Chinese knock-off of the genuine HP article.
Finally, this is closely allied with the economic idea of the difference between up-front costs and total lifetime costs.

Economics is full of stories of long-term purchases made looking only at short term up-front costs when a more rational analysis would be on discounted full-lifecycle costs.

In general, homebuyers won’t pay for energy efficiency imrovements with even 2- and 3-year times to payback. Homeowners won’t buy retrofit improvements the same way.

The incandescent vs CFL example is much clouded by the fact that CFLs are an obviously poor substitute for incandescents. But the point remains.