Thus, although capital investment ultimately boosts output per hour, these adjustment costs temper the initial benefits to increased production obtained from new investment. It is likely that as capital spending fell over the past couple of years, so did the disruptions that accompanied its installation. Moreover, the dislocations associated with the substantial investment of the late 1990s and 2000 also likely were waning.
This lower level of disruption provides a boost to growth in output per hour for a time. How much remains an open question. The quantitative evidence 2 on the magnitude of this effect spans the range from significant to small.