Quartz Daily Brief—Americas edition—Oil keeps falling, Democrats debated, pizza-slicing mathematics

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What to watch for today

Oil prices are falling after Iran sanctions ended. Crude oil dropped to below $29 per barrel on anticipation of a surge in supply after the US and EU certified that Iran had complied with the terms of a landmark nuclear deal. That meant the lifting of sanctions and allowing the country to export oil freely.

The global business elite arrive in Davos. Fire up the private jets: attendees of the World Economic Forum are heading to Switzerland ahead of the annual confab, which begins on Tuesday. World markets are off to their worst start in more than four decades, but WEF founder Klauss Schwab is optimistic that technology could bring us together.

Will Beijing’s currency prop help markets? The central bank said it would introduce a reserve-requirement ratio for some banks dealing in the offshore yuan. It hopes that would reduce liquidity in the currency and end a massive selloff by speculators, perhaps calming markets globally.

It’s a holiday in the US—sort of. Most financial markets are closed to mark the 30th anniversary of the holiday honoring slain civil-rights leader Martin Luther King, Jr. But fewer than half of US workers will get a paid day off.

Over the weekend

US Democratic presidential hopefuls debated. Gun control and healthcare were the main points of contention between Hillary Clinton and Bernie Sanders, in the final debate before a crucial vote in Iowa. Clinton, who aligned herself closely with president Barack Obama, also accused Sanders of threatening to damage Obama’s progress. Sanders unveiled a universal healthcare plan.

More stocks in the Asia-Pacific and Middle East fell… Japan’s Nikkei 225 and Australia’s S&P/ASX 200 both declined to 19% lower than their recent peaks, putting them just a single percentage point away from an official bear market. Falling oil prices contributed to the glum mood; Saudi Arabia’s Tadawul All-Shares Index fell by 6.5% on Sunday and it is down by 0.4% again today.

…but investors returned to China’s property market. New-home prices rose by 1.6% in December compared to a year earlier, marking their third consecutive year-on-year increase, after a long period of declines. That likely contributed to a modest rise in China’s stock market, which ended the day’s trading higher.

Taiwan elected its first female president. Tsai Ing-wen, the pragmatic leader of the independence-leaning Democratic Progressive Party, trounced her opponent from the relatively pro-Beijing Nationalist party. Beijing warned Taiwan to abandon its “hallucinations” of independence.

Ebola fears gripped Sierra Leone again. More than 100 people were quarantined after tests revealed that a 22-year-old woman who died last week was suffering from the viral disease. The WHO confirmed the new case—just one day after it declared West Africa Ebola-free.

Quartz obsession interlude

Olivia Goldhill on American vs. British spellings of words. “English has used both endings for several centuries. Indeed, the first three folios of Shakespeare’s plays reportedly used both spellings equally. But by the late 18th and early 19th centuries, both the US and the UK started to solidify their preferences, and did so differently.” Read more here.

Matters of debate

The Agricultural Revolution was history’s biggest fraud. The average farmer worked harder than the average forager, for a worse diet.

The world should bring Vladimir Putin in from the cold. Japan’s Shinzo Abe argues for re-engaging with Russia (paywall) to tackle crises in the Middle East.

Bernie Sanders’s ideas don’t fit with US political reality. There’s no way his ambitious projects could make progress in the nation’s divided government.

Surprising discoveries

Shanghai’s largest vacant building is a Pentagon-shaped shopping mall. It’s even bigger than the original in Washington.

There is a subset of mathematics devoted to slicing up pizzas. Monohedral disc tiling” produces an unlimited number of equally-sized pieces.

Women instinctively guard their sexual partners from others who are ovulating. Humans are subconsciously aware of each other’s fertility.

South Sudan’s first and only brewery is closing. There’s simply not enough foreign currency to buy raw materials.

It’s really difficult to play guitar in space. Canadian astronaut Chris Hadfield says weightless strumming is a lot harder than it looks.

Our best wishes for a productive day. Please send any news, comments, orbital guitar solos, and South Sudanese beer to You can follow us on Twitter for updates throughout the day.

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