Isn't the world economy built on the idea that markets will always go up? Every year should be an all time high, otherwise we're in recession which is (apparently) tragedy to be avoided at all costs, no?

The 'business cycle' of expansion and contraction is obviously visible in history and has reasonable macroeconomic explanations, and it's expected to continue.

People try to predict the timing of it (which is hard because acting on these predictions often alters reality so that they're less likely to come true), and they definitely try to ensure that recessions aren't long and hard and that the economy can recover from them faster, but nobody is saying that they can prevent a recession, and the interventions which can artifically postpone a recession (i.e. postpone a correction of some market) would generally only make the recession much worse when it happens.

It is less the assumption that the market always goes up (eventually) and more the lack of mathematical comprehension.

1987 saw a massive market crash with no recession.

This is the most hated bull market ever. None of the experts are buying heavily into this market (it's all stock buybacks that's driving this market up).

So, you can see why everyone is uneasy about these extremely high PE ratios.

What index are you looking at? SP 500 is at about 23 [0] which while higher than median, is definitely not at all time highs.

[0]: https://www.multpl.com/s-p-500-pe-ratio/table/by-month

Not really. Recessions are where there is less spending and production, not when the stockmarket goes down.

While stockmarkets and property prices and the like to tend to go up and up in nominal terms a lot of that is because of the currency they are denominated in losing value through inflation. If you adjust for that there is much less of an uptrend.

When you take the logic to such extremes, it becomes a meaningless statement. It's literally impossible to disprove this assertion if you just ignore the evidence that says it's not true. Japan is absolutely a counterexample.

Considering an impending recession, it just makes sense he would dump these now.

Certainly in raw numbers the market is in territory that is, while not unprecedented, associated with a couple previous rather significant collapses. It's safe to say a recession will happen but difficult to say exactly when.

The country is incredibly divided. About half the country thinks the country is going to shit anytime their party isn't leading. The country usually does go to shit when leadership is divided. And the economy has almost always gone to shit when the yield curve inverts. Combine that with the fact that inequality is at an all time high and a lot of people WANT to see asset prices go to shit, a lot of people want to see this administration go to shit, and you've got a recipe for people predicting and cheerleading recession.

I'm young, so I can hardly speak of 2007 at all, but I think this is a unique circumstance in the amount of people that seem to WANT a recession. Would love to hear from someone older and wiser if this aspect is normal.

Will there be a recession? Yeah. When, is the trick, it could be tomorrow or 10+ years from now. That recession will also be followed by a boom. Such is life. That we have not had one recently is a bit unusual but not unprecedented. You could even argue the the world is already in the 'coming' recession, minus the US.

I would posit people wanting a recession is just a form of jealously and resentment. Normal? Not in my experience. But then I may have just not noticed. I remember the gas lines of the 70s. No one really wants that just to feel smug, do they?

For the past few years many macro indicators (Shiller PE, Market Cap to GDP, etc...) have signaled that returns will not be in line with the recent uptrend. This doesn't mean there will be a crash, it could also signal an extended period of reduced returns.