Imagine: no more used book stores; no more lending a book to your friend; no more borrowing one from the public library—no more “leaks” that might give someone a chance to read without paying.

For instance, encourage the kids to look for ways to save money - by borrowing DVDs from the public library instead of renting them, or saving electricity by turning out lights.

Along the way the public perception of liquidity changed, from one based on assets (what you could sell) to one centered on liabilities (ease of borrowing).