By Chris Dorrell If you ask economists what the biggest problem facing the UK economy has been over the past few decades, most would say low levels of investment. Investment in new technologies is crucial for stimulating productivity growth, but the UK economy has the lowest level of investment compared to GDP in the G7. Perhaps unsurprisingly, the UK’s productivity growth has been more sluggish than that of its rivals. However, economists at Deutsche Bank have questioned this narrative. “Weak UK investment was not a reason for sluggish UK growth these last few years,” Sanjay Raja, chief UK ec…