Semi-skilled workers are being left out of work due to technological advances and automated workplaces, resulting in an 'hour glass' shaped labour market, according to recruitment firm Hays.

In their report 'Creating Jobs in a Global Economy, 2011-2030', Hays says that technological change in the past 20 years is forcing out the world's middle group of semi-skilled workers.

Jobs that involve routine actions have commonly been replaced by automated machines, while service sector jobs such as bookkeeping, data processing and call centre operation are also under threat from advancements in technology.

"On the other hand, non-routine jobs have generally become more productive and valuable with the use of new technology," said Nigel Heap, managing director of Hays.

"The same applies to occupations where face-to-face contact cannot be replaced with a machine, such as in healthcare and education."

In general, demand for labour in routine, low-skilled occupations has remained unaffected. Jobs in cooking, cleaning, building and driving have increased, as computers and machines cannot replace workers in these sectors. This results in the 'hour glass' effect, with employment rising at the top and bottom ends of the skills ladder, while the semi-skilled workers in the middle are being squeezed out.

According to Hays, it is not just job numbers that are impacted by this 'hour glass' phenomenon. The trend is also impacting on wage levels. Those at the top of the income distribution have seen their wages rise relatively quickly over the last decade, while the middle group has experienced stagnation.