> Time and time again large competing forces in the market are found to have colluded instead of directly competing with each other to drive price/cost down.

Collusion and cartels never work on the long run. It's an unstable equilibrium, the incentive to reduce prices to capture more market is too great.

> What is it that still makes you believe

Competition. It's the only force keeping humans honest. That's why we must treat any barriers of entry in a market with extreme care. The only "failed" or "captured" market is a strongly regulated one.

Markets can remain irrational, or colluding, far longer than you can stay solvent (or even alive).

For example, while the Phoebus cartel only really lasted from 1925 through to 1939, 1000hr incandescent light bulbs remain the standard offering till present day. Profitable market manipulations are sticky.

The whole notion that markets are efficient is just a mathematical construct that has become very dogmatic for people. But if you look into the details, markets are efficient under the assumptions of perfect information and infinite time. Neither of those conditions are present in the real world: we neither have perfect information nor infinite time.

> Competition. It's the only force keeping humans honest.

Pure misanthropic fantasy pretending to be sophisticated economics.

> Collusion and cartels never work on the long run.

Define "long run" - they have been already proven to have worked for years and in some cases even decades.