Lots of stuff happened in the 1970s. It's requires a huge leap of logic to say that computers are the cause... after all correlation does not imply causation. You need significantly more evidence to prove that computers are the cause of the growing wage gap.

There was a really famous book that was published recently called "Capital in the 21st century" by Thomas Piketty that summarizes the real reason:

http://www.economist.com/blogs/economist-explains/2014/05/ec...

The book is dense, but the logic and evidence is compelling. Basically it says that you need to look at more data, because there was ALWAYS a trend towards inequality that was temporarily reversed from 1930-1975, read below:

""Capital" is built on more than a decade of research by Mr Piketty and a handful of other economists, detailing historical changes in the concentration of income and wealth. This pile of data allows Mr Piketty to sketch out the evolution of inequality since the beginning of the industrial revolution. In the 18th and 19th centuries western European society was highly unequal. Private wealth dwarfed national income and was concentrated in the hands of the rich families who sat atop a relatively rigid class structure. This system persisted even as industrialisation slowly contributed to rising wages for workers. Only the chaos of the first and second world wars and the Depression disrupted this pattern. High taxes, inflation, bankruptcies, and the growth of sprawling welfare states caused wealth to shrink dramatically, and ushered in a period in which both income and wealth were distributed in relatively egalitarian fashion. But the shocks of the early 20th century have faded and wealth is now reasserting itself. On many measures, Mr Piketty reckons, the importance of wealth in modern economies is approaching levels last seen before the first world war."

The real reason for economic inequality is not technology, it is actually a feature of capitalism. In simple terms what is happening is that invested wealth grows faster for rich people then it does for poor people and this causes the gap to grow. See the quote below:

"From this history, Mr Piketty derives a grand theory of capital and inequality. As a general rule wealth grows faster than economic output, he explains, a concept he captures in the expression r > g (where r is the rate of return to wealth and g is the economic growth rate). Other things being equal, faster economic growth will diminish the importance of wealth in a society, whereas slower growth will increase it (and demographic change that slows global growth will make capital more dominant). But there are no natural forces pushing against the steady concentration of wealth. Only a burst of rapid growth (from technological progress or rising population) or government intervention can be counted on to keep economies from returning to the “patrimonial capitalism” that worried Karl Marx. Mr Piketty closes the book by recommending that governments step in now, by adopting a global tax on wealth, to prevent soaring inequality contributing to economic or political instability down the road."

I'm no economist but according to my knowledge this is the prevailing theory in academia today.