“Pointing out to people that ‘perfect competition’ is assumed in simple modeling is “muddying the waters”.”
I never said that.
Simple modeling includes perfect competition. It also includes monopoly, oligopoly, monopolistic competition, and duopoly. Nor are these meant to be collectively exhaustive and complete. These are an introduction to economic thinking. Each teaches the student something. There will always be additional challenges in application.
You seem be arguing against economics generally. That is where you muddy the waters.
Investopedia is no substitute for a classes in economics.
“Real-world competition differs from the textbook model of perfect competition in many ways.”
Duh. There are several models as I mentioned, not just perfect competition. And as I mentioned above, there are challenges in application. That there are challenges in application should not be used by you as an excuse to disregard all theory.
“Real companies try to make their products different from those of their competitors. They advertise to try to gain market share. They cut prices to try to take customers away from other firms. They raise prices in the hope of increasing profits. And some firms are large enough to affect market prices.”
There is nothing in that quote that would surprise textbook authors - or readers for that matter.
“Simple modeling includes perfect competition. It also includes monopoly, oligopoly, monopolistic competition, and duopoly. “
That’s an odd comment because simple supply and demand models assume perfect competition. Any model adding imperfect competition is of necessity not simple
“You seem be arguing against economics generally.”
Two can play that game.
“Investopedia is no substitute for a classes in economics.”
I didn’t say it was. However that investopedia information is standard stuff given in introductory econ courses to warn students that theoretical models differ from empirical models.