How the spread of the novel coronavirus, also known as COVID-19, plays out may have an impact on the presidential election in November, a team of Wall Street analysts says.

The Democrats have yet to choose a candidate to challenge US President Donald Trump, but a sharp and prolonged economic downturn could change the electoral calculus despite record low unemployment and solid wage growth, they said.

"History shows that US presidential re-election probabilities are highly dependent on second-quarter US gross domestic product growth," Goldman Sachs analysts said.

"If the COVID-19 becomes widespread and leads to a slowdown in US growth or a recession it could alter current expected election outcomes."

The investment bank Goldman Sachs plotted both optimistic and pessimistic courses:

If the global spread of the coronavirus is brought under control quickly and if supply chain disruptions are minimal, the US and world economies will rebound in the second half of the year.

But if the supply chain is broken and production severely disrupted, US and global demand will fall. National economies worldwide will contract in both the first and second quarters and the world will slide into recession.

"Our new baseline scenario involves a continued slowdown in infections in China that allows for a slow recovery in indicators of economic activity," the firm said in a research report to investors.

"However, it also includes moderate supply chain disruptions in the global goods producing sector as well as a hit to consumer spending and business activity from national outbreaks that go well beyond China. All else equal, this would imply a short-lived global contraction that stops short of an outright recession."

Nevertheless, the Goldman Sachs analysts expect no earnings growth in US companies this year because of a sharp decline in Chinese economic activity, lower demand for US exports, supply chain disruption and increased economic uncertainty.

That is likely to mute the market because investors seek growth.

In the short-term, last week's market drop of more than 3,500 points, is likely to mean a shift to defensive stocks and away from those offering the prospect of high growth and hefty returns.

Investors are likely to move to real estate companies that generate about 81 percent of their revenue in the US. Utilities offer similar strengths and have historically offered attractive valuations.