The best players will avoid trying to make an exploitative decision (e.g. guessing the correct level the opponent is thinking on), and instead make something approaching a game-theoretically optimal one (e.g. a maximally unexploitable strategy).
For example, if you're facing a big bet where you can only beat bluffs (e.g. all missed draws), but lose to any value bets (e.g. sets, straights, flushes), then you'll need to mainly be folding, but to avoid being exploitable you'll also need to call down with some percentage of these mid-strength hands (where the exact number depends on the bet size relative to the pot).
To decide which bluff-catchers you want to call down with, you'll want to pick hands that don't block any of your opponent's bluffs (e.g. you don't want to be holding the Ace of Spades on a flop that had two spades but a third didn't come by the river, since having this card eliminates a number of likely missed flush draws that your opponent might be bluffing with). In addition, you'll also want to pick hands that DO block some of your opponents value bets (e.g. your hand contains one or two cards that block your opponent from having straights, flushes, sets).
Naturally, calling down with the correct ratios is rather hard and only the best players can do so with any consistency, but it does remove the whole levelling guess work and reduces the decision to something you can reason about.
I agree that price is simply a measure of what the market will bear, but I don't see how a basic income results in exhausting the additional supply of disposable income through inflated prices.
To continue with your apple market example, you could try to charge $2 or more per apple, but pretty soon other people will realise that they can employ their own staff to run an orchard and deliver apples to the same market at a marginal cost far less than that, and competition will drive the market price back down.
With a basic income, people's basic needs would be met and any additional income earned would be a supplement. If they agree to work for $1 an hour picking apples, then that is the price the market will bear for that particular skill and the price for a single apple will be reflective of this.
A minimum wage on the other hand works in the opposite direction. If it is set to $50 an hour, then sure, the costs of apples, along with most other things, will skyrocket, but there will also be a huge amount of deadweight loss as people simply choose to forgo employing others for many skills in the first place.
The economics of publishing are such that the authors choose to add every area they can on a given topic so that people won't reject their book for another on the basis of one missing item.
As others point out, it is also a crude proxy that buyers use to evaluate the worth of the book without reading the entire thing.
Of course, there are exceptions. One of the reasons that The C Programming Language by Kernighan and Ritchie is so popular is its conciseness.
You're right, I could have chosen a better title. This article may have been looking at correlations after the fact, but the conclusion is that present changes in search volume can provide insight into future market movements.
Of course, any real opportunity for a profitable trading strategy using this information would be quantified and reflected in prices, so I don't expect the results to persist over time, but I found the findings interesting nevertheless.
For example, if you're facing a big bet where you can only beat bluffs (e.g. all missed draws), but lose to any value bets (e.g. sets, straights, flushes), then you'll need to mainly be folding, but to avoid being exploitable you'll also need to call down with some percentage of these mid-strength hands (where the exact number depends on the bet size relative to the pot).
To decide which bluff-catchers you want to call down with, you'll want to pick hands that don't block any of your opponent's bluffs (e.g. you don't want to be holding the Ace of Spades on a flop that had two spades but a third didn't come by the river, since having this card eliminates a number of likely missed flush draws that your opponent might be bluffing with). In addition, you'll also want to pick hands that DO block some of your opponents value bets (e.g. your hand contains one or two cards that block your opponent from having straights, flushes, sets).
Naturally, calling down with the correct ratios is rather hard and only the best players can do so with any consistency, but it does remove the whole levelling guess work and reduces the decision to something you can reason about.