1) Governments and central banks have made it clear they will not allow massive deflation, which removes the big risk from owning stocks. Stocks do well in both mild deflation and mild inflation, and they pass through the fire of hyperinflation with little damage once the hyperinflation ends (though profits are all taxed away while the hyperinflation is in progress). But massive deflation is deadly to stocks, because of possibility of bankruptcy. Removing risk of bankruptcy means equity risk premium will be much lower henceforth. "Reversion to mean" PE will be more like 20 than 15 (and CAPE-10 more like 25 than 20). That is, stocks will be much more expensive in the future than in the past: "at a permanently high plateau". Or, if not permanently, then until world is ready to allow massive deflation again.
2) Higher real interest rates will be needed to prevent hyperinflation. High real interest rates hit stocks, real estate and commodities, including gold. Because all asset prices are currently inflated from low interest rates, it will not take significantly high real interest rates to have a moderating effect on inflation.
3) Gold ultimately is anchored to mining costs, which are about $1300/oz currently, average for all gold mines worldwide. Mining cost should go up in line with energy costs. In other words, gold at $1300/oz or less will hold value indefinitely (provided people continue to want to hoard gold, which is a reasonable though not guaranteed bet), while gold at higher prices is a bet on demand (mostly hoarding demand, since gold has few industrial uses) outrunning mining supply. This bet can succeed for a few years, but not permanently. Higher real interest rates shorten time required for bet to fail.
4) Wage/price inflation is ultimately caused neither by money printing nor aggregate supply outrunning aggregate demand, but rather by aggregate political power of those who want inflation exceeding aggregate political power of those who want deflation. If the will for inflation/deflation is there, the way is obvious: give everyone $1 million for inflation, tax wealth at 99% for deflation, as extreme examples. Argentina, among others, has a perpetual will to inflation, and thus perpetually finds a way to achieve it.
Obviously, bondholders want deflation, but now that central banks are the major owner of government bonds, that constituency is of diminished importance. Remaining pro-deflation constituencies are: elderly with lots of cash (short bonds, bank accounts); elderly on fixed pensions (not adjusted for inflation); "little" people who hate for prices to go up even if their wages go up more. Constituencies for inflation: owner of real estate, especially with mortgages; corporations and their stockholders, especially corporations with debts or pension liabilities; governments with pension liabilities. 40 years ago, sea change occurred throughout developed world when forces wanting deflation finally gained upper hand versus forces wanting inflation. IMO, we are about to see sea change in opposite direction in next few years.
5) Baby boom in developed world was roughly 1950-1959, thus peak at 1955. Peak hit age 20 in 1975, causing maximum inflation as peak boomers went into debt to get married, set up independent households, buy cars and houses, while being unproductive workers because not yet trained. Push for deflation in 1980 was driven by elite, who gained power then for various reasons, including discrediting of communism in Soviet Union, and thus dimished need to appease worker class elsewhere. Peak baby boomers hit age 55 in 2010, and began to save furiously for retirement, adding to existing deflationary forces. Peak hit 65 in 2020, and thus savings glut due to boomers should soon start receding. Dis-saving by elderly should become significant by 2025, when peak reaches age 70. Dis-saving includes spending down of accumulated private wealth (housing equity, stocks, bonds) plus spending by corporations and governments on pensions and medical expenses. Sea change from savings to dis-savings by boomers will be highly inflationary.
6) Developing world baby boom, especially in China, is delayed relative to that in developed world. So possibly continuing massive deflationary savings (trade surpluses) by China, etc will offset massive inflationary dis-savings in developed world.
7) Japan bubble of 1989, USA tech/telecom bubble of 2000, USA housing bubble of 2007, related to demographics, though loosely. Investment bubbles are constant phenomenon because of humans naturally like to gamble, so impossible to drawn too many conclusions from such bubbles.
8) Current social unrest in USA, and likely future unrest in Europe, is threatening to elite. Path of least resistance is to buy peace with lots of inflationary government deficit spending.
9) Constant theme of these thoughts is that inflation is coming sometime in next decade, and likely sooner than later. Real interest rates will eventually be higher to control inflation, but not massively higher. Gold is no safe refuge in long run. Nominal bonds and cash will both lose to inflation. Inflation-indexed bonds pay 0% real currently, so will lose when real rates go positive.
10) Real estate normally survives or even thrives under inflation, but maybe not expensive urban real estate that might be affected by migration to exurban satellite towns: close enough to drive to city occasionally, far enough away to be cheap and safe from big city problems. Quick access to city no longer needed due to telecommuting or movement of both workers and businesses to exurbia. Quick access no longer wanted in pandemic-conscious era.
11) Value stocks likely to survive inflation far better than growth stocks. In particular, financial stocks will benefit from steep yield curve. Basic materials and energy stocks produce useful commodities, and should do better than sterile gold in a vault, especially if they have substantial long term debt or pension obligations that cam be inflated away.
12) US dollar likely to lose its reserve status in favor of basket of currencies. No need to international agreement for this to happen. Businesses can simply write contracts to be paid 33% dollars, 20% euros, 10% yen, 5% british pounds, and so forth. Eventually, everyone will settle on a standard combination of currencies for contracts, and then revise this standard every 10 years. Loss of reserve status for dollar will have many effects, including more inflation in the USA.
13) USA big tech stocks (Apple, Microsoft, etc) are good businesses with good future, but this is more than reflected in prices. These stocks could easily fall 30% over next few years relative to value stocks, as euphoria dissipates. Because of inflation, they may not fall in absolute terms.
14) It is tempting to market time: sell stocks in anticipation of crash while buying gold in anticipation of bubble, then trade gold for stocks later. Actually succeeding with such market timing is very difficult. Over very short intervals (under a week), you are competing with Renaissance Technologies and will surely lose. Over medium intervals (under three years), you are competing with hedge funds and need to be smarter than them to succeed: unlikely. Over long intervals (beyond three years), competition diminishes because of "career risk" in hedge funds: they cannot underperform for long periods without losing their clients. Only competition for long term market timing is other individuals, and there is not enough wealth controlled by smart individuals doing long term market timing (aka tactical asset allocation) to compensate for wealth controlled by herd followers who create bubbles.
When engaging in long term market timing, remember that both bubbles and periods of gloom can go on for very long periods. Sell SLOWLY into bubbles. Buy when price is good, fully expecting good prices to become better immediately after you buy: that doesn't negate your good price.
15) For the record, I'm up 4% this year as of today. Currently 29% USA stocks (value stocks only, tilted small value), 4% rest of UCAN block (USA, Canada, Australia, New Zealand), 18% europe, 15% japan/korea/se asia, 13% china/hong kong/taiwan, 13% russia, 6% other emerging markets, 1% cash. Other than USA, which is tilted value, other ETFs are market cap weighted indexes, mostly from Vanguard, other than ERUS and RSX for Russia. Russia is a huge bet on energy, basic materials and mining, optimistic view about future of Russia in case of worst case global warming scenario, geo-political diversification, cheap ruble, incredibly cheap PE and PB ratios.
I consider myself a very conservative investor, much more concerned about wealth preservation than growth. Because of massive bias towards inflation by governments everywhere, 99% stocks feels safer to me than bonds or cash.
For personal reasons, I don't want to own real estate currently. Otherwise, I would definitely diversify into exurban or rural real estate with part of my wealth.