New study shows importance of technological change in the macro economy

One of the punchlines of macroeconomics is that technological change is a fundamental source of long-run economic growth.  And if it has long-run effects, surely it has short-run effects as well and therefore could affect what is commonly known as the business cycle.  But measures of technological change for a nation as a whole are difficult to come by.  Now there comes a recent study by Michelle Alexopoulos from the University of Toronto that uses an ingenious measure of technological change based on the number of new books titles published on technology.  Using that measure, Alexopoulos finds, as expected, that technological changes have been an important source of short-run fluctuations in the economy thus providing support for the importance of supply-side factors in the macro economy.