Beyond the freer hand for big tech companies, Mr Trump will also preside over a reordering of the regulatory landscape.

He has vowed to give energy companies more freedom to drill for oil on federal land and will probably lift a moratorium on the export of liquid natural gas.

His second administration could also herald an easing of the onerous reporting requirements placed on banks after the global financial crisis of 2007-09.

At the same time, Mr Trump may claw back some of the rules and subsidies drawn up by the Biden administration to encourage Americans to use renewable energy.

Winners and losers in the stockmarket reflected this reshuffling.

First Solar, America’s biggest manufacturer of solar panels, plunged by 10% the day after the election, while big banks such as Bank of America were the mirror image of that, climbing by 8%.

Tariffs will be Mr Trump’s most controversial set of policies, especially in foreign capital cities.

Central to his programme for nearly a decade has been a belief that protectionism is essential to American prosperity.

His first term in the White House, which featured tariffs on steel from around the world and on a range of Chinese products, is probably just a prelude to what he will attempt now.

He has talked about slapping levies of 10-20% on everything that America imports, of 60% on all goods from China and even higher duties—perhaps 500%—on cars from Mexico.

Almost universally, economists say such hefty tariffs would lead to higher consumer prices and act as drags on investment and growth.

That is a potentially cruel irony for American voters given that anger about inflation under Mr Biden helped fuel support for Mr Trump’s re-election.

Many Republicans in Congress are also less enthusiastic about tariffs; a traditional free-trade strain remains alive, if hardly thriving, in the party.

But any opposition from them may not amount to much.

Mr Trump’s advisers, notably Robert Lighthizer, America’s trade representative in his first term, have been drawing up plans to use executive orders and hitherto untested emergency powers to impose across-the-board tariffs.

Whether those powers will actually function as they hope is unclear.

Companies are sure to challenge the tariffs in court and may succeed in overturning them.

So Mr Trump may start with smaller and more targeted tariffs before shooting for universal levies.

Tariffs are also sure to invite retaliation.

In Europe officials have already drawn up lists of levies that they may impose on American goods.

China will probably go after farm products, from soyabeans to corn.

Other countries will be tempted to follow suit but will also try to carve out exemptions from Mr Trump’s tariffs.

That will be especially true for Canada and Mexico, whose fortunes are closely yoked to trade with America; the peso fell to a two-year low the day after the election, before regaining some lost ground, amid fears that Mr Trump’s tariffs could spell trouble for the Mexican economy.

Given the size and diversity of its economy, America may be better insulated than most from a global trade war—that, along with the higher Treasury yields, helps to account for the dollar’s rise after Mr Trump’s victory.

The very real danger for the world is weaker growth, higher prices and more brittle supply chains.

Mr Trump’s plan to “fix” America’s borders—a constant theme of his campaign—is another source of uncertainty.

If he keeps his promise of mass deportations, these would take a huge toll on the economy by shrinking the workforce.

Booting out 8m migrants would reduce America’s GDP by 7% versus baseline expectations by 2028, according to estimates by the Peterson Institute for International Economics, a think-tank.

But the actual number is unlikely to come close to that.

Any attempt to deport millions will run into stiff resistance, with local officials in some of America’s biggest states, from California to New York, refusing to co-operate.

A more realistic outcome may thus be much stricter enforcement of border controls, which would stem the inflows of illegal migrants seen under Mr Biden.

That in itself may translate into labour shortages for restaurants, construction companies and more, imparting yet another inflationary force.

How Mr Trump approaches legal immigration could make things worse—or better.

In his first term he pared back green-card issuance, but in campaigning he has suggested that he might consider easing immigration rules for foreign students.

Given that America’s native-born workforce will shrink as the population ages, Mr Trump will face real economic pressure on this front.

“We do need immigration to hold up for potential economic growth to stay healthy,” says Satyam Panday of S&P Global, a credit-rating agency.

There are other threats, too.

Worries about inflation are likely to weigh heavily in the Federal Reserve’s calculations.

The rise in Treasury yields shows that many investors believe the central bank will end up leaving interest rates higher next year than previously assumed—though they still expect a quarter-point cut at its meeting on November 7th, after we published this.

A more hawkish Fed may, in turn, invite the wrath of Mr Trump, who has insisted that, as president, he should have a say over interest rates.

He will surely want to see steeper rate cuts now that he is in charge.

Legally, he can do little to control the Fed, but his advisers have talked of creating a “shadow Fed” to try to steer its decisions.

The spectacle of the president attacking the central bank may spook markets but the Fed’s statutory independence should keep it well protected.

That Mr Trump may not be able to realise his most extreme ambitions should offer some solace to an anxious world.

But he will probably be able to push further in his second term than he did in his first.

He is better prepared for governing this time, with a larger team of loyalists and a more detailed plan of action.

It is going to be a turbulent economic ride, for America and the world.

Buckle up.