In his Q1 2015 Global Macroeconomics report, HSBC pointed out that for many economists, lower oil prices are like “manna from heaven”.

“By raising real incomes in high-cost parts of the world, lower oil prices represent not only a redistribution of income from oil producers to oil consumers, but also a blow to global demand,” the report said.

“According to this interpretation, the global economy suddenly looks much better than it did in the first months of 2014,” it said.

But such a view may be too optimistic, HSBC said.

If lower oil prices represent only an increase in supply (thanks to higher production in the US and Libya), the impact on the global economy will be "unequivocally positive".

"If, on the other hand, falling oil prices are a sign of broader deflationary patterns, then there is more cause for concern," HSBC said.

"In our view, deflationary pressures were well established long before oil and other commodity prices fell, suggesting that the global economy remains in relatively poor shape," the report said.

The biggest problem for the global economy, as far as HSBC is concerned, is "still high" debt levels.

"Across the developed world, there is no real sign that deleveraging has helped reduce overall debt levels," HSBC said.

"At best - as in the US - lower levels of private debt are offset by higher levels of public debt," it said.

Moreover, monetary policy appears to have limited power at high levels of debt, HSBC said.

"With interest rates at zero and after years of central banks pursuing various forms of unconventional easing, there are very few signs of renewed credit growth: the echoes from Japan are increasingly difficult to ignore," the report said.