The author is the chief global strategist of Morgan Stanley Investment Management, and the author of “Ten Rules for Successful Countries”

Although economists expect the reopening of the global economy to roar in the next few quarters, there are two increasingly pressing reasons to question its intensity and duration: China and the United States. These two superpowers are the locomotives of global growth, but their economic engines are cracking.

In the past five years, China alone accounted for more than one third of world economic growth. Today, a 1 percentage point slowdown in China’s economy will reduce global GDP growth by a third, so when Beijing tightens the screws, the world has reason to worry. With the crackdown on the technology industry, this is happening.

In recent years, as old economic industries such as commodities and manufacturing have fallen into debt and recession, China’s prosperity has been supported by a new economy centered on the technology industry. In the past ten years, the share of the digital economy in China’s GDP has quadrupled, reaching an astonishing high of 40%.

But as the ruling party tries to revive the socialist values ??in the early stages of the revolution, the technology giants may pose a long-term challenge to the ruling party.No tycoon in China is worth more than 10 billion U.S. dollars ten years ago; There are nearly 50 people now. In the past year, China has added 238 billionaires, more than double the number of other countries. Most of the wealth comes from technology.

The crackdown was seen as a healthy measure to curb monopoly, or the state’s attempt to control big data. However, the reaction of the Communist Party to this unprecedented surge in wealth and inequality is not surprising.

This new movement follows the old model, dating back at least to the economic czar Zhu Rongji in the early 1990s. In the past 40 years, as the country regressed, China has emerged as an economic superpower, allowing capitalists to release to promote growth. But sometimes, when the obvious excesses of capitalism—corruption, debt bubbles, or inequality—become out of their liking, state managers step in to curb capitalism.

This movement is usually accompanied by an economic slowdown, but it ends before the damage is severe. About ten years ago, Beijing launched a large-scale anti-corruption campaign and laid off many rich people, who were quickly replaced by a new generation of technology giants.

This time, the stakes seem to be higher. It is difficult to see how any other sector can compensate for the impact on the digital economy, and the losses are already obvious. Since the beginning of the crackdown, the market value of China’s technology has fallen by a third, to about $1 trillion. The rise of new technological unicorns has dried up. Given how powerful the technology giants have become and the widespread belief that data is the new gold, it is unclear whether Beijing is prepared to make concessions.

The United States is the world’s second largest economic engine, accounting for about one-fifth of global growth in the past five years. Many forecasters believe that the US$2.5 trillion in extra savings that Americans saved during the pandemic will greatly promote global recovery, and with the full reopening of the economy, it is speculated that these savings will now be spent.

However, the behavior of consumers in the past was not the case.

As pointed out in a recent article in Barron’s, only countries that have been defeated and unstable in war will release excess savings in a consumer frenzy. Consumers in these countries worry that their currencies may change soon. It’s worthless. In the United States, the last major event of mandatory savings occurred during the Second World War. The United States won, instead of spending wildly after the war, Americans have been sitting on these extra savings for years.

Now the conditions are similar. Americans choose to spend only about a third of the pandemic stimulus check, saving or paying off debts with the rest. The new Delta variant may reinforce this caution.

The United States is also approaching the “fiscal cliff.” In the coming months, new government spending will drop sharply. Most economists hope that additional strong consumption growth will make up for this shortfall. But history is not on their side. After stimulating the sugar market, growth tends to fall back quickly.

Signs of engine failure flashed in China and the United States, and accounted for more than half of the global growth in recent years. Although fierce debate in the financial markets has focused on whether the rise in inflation will be temporary, it is time to consider whether the economic boom will be shorter than expected.