The Organisation for Economic Co-operation and Development (OECD)(www.oecd.org) — a group of 34 countries founded in 1961 to stimulate economic growth and world trade — has warned that a lack of investment by governments and business has left the global economy vulnerable to another slowdown.

It argues that the world-wide recovery since the financial crisis has been “unusually weak, costing jobs, raising inequality and affecting living standards”.

In its latest Outlook report, the Paris-based organisation says that the economy will not return to the average rate of pre-crisis growth until late 2016.

OECD chief economist Catherine Mann said: “The world economy is muddling through with a B-minus average, but if homework is not done and with less-than-average luck, a failing grade is all too possible. On the other hand, the way to get an A is known and is within reach — more investment from both business and governments.

“Despite tail-winds and policy actions, real investment has been tepid and productivity growth has been disappointing.

“By and large, firms have been unwilling to spend on plant, equipment, technology and services as vigorously as in previous cyclical recoveries.

“Moreover, many governments have postponed infrastructure investments as part of their fiscal-consolidation plans. Even if investment does accelerate, output growth will still look anaemic compared to past decades.”

Meanwhile, the OECD has cut its projection for US economic growth to 2% this year (from a forecast of 3.1% at the beginning of March).

The organisation predicts that “an uncertain economic growth outlook and low inflation” will mean that the US central bank is likely to avoid raising interest rates this year.

Turning to the UK, the OECD said that more must be done to tackle low levels of productivity. The Outlook report said: “Stronger investment is needed to revive labour productivity, wages and competitiveness and to balance the housing market.”

The organisation has also downgraded its forecast for UK economic growth in 2015 to 2.4% (from its 2.6% forecast in March).