Thomas Malthus was wrong for one simple reason. Humans have survived his 1798 forecast that growing populations wouldn't be able to feed themselves because innovation and productivity gains allowed them to produce more and more with the same amount of labor and capital: Irrigation, fertilizers, higher-yielding plant species and mechanization have enabled farmers to grow 5 to 6 times the amount of grain from the same piece of land as a century ago. The problem is that similar productivity gains may no longer be possible - or effective.
There's general agreement about the factors that improve productivity. Investment in machinery and equipment increases production levels and quality. Education and training improve worker skills. New products, technologies, organizational structures and work arrangements - in other words, innovation - raise efficiency. A healthy climate for entrepreneurship and competition encourages the creation of faster, smarter businesses.
Unfortunately, there's also general agreement that productivity gains are flatlining. In advanced economies, productivity growth has fallen below 1 percent annually, significantly lower than the 3 to 4 percent common in postwar decades and even less than the 2 to 2.5 percent of the last decades of the 20th century. Similar trend lines are beginning to appear in developing nations. Combined with stagnant or declining workforces, slowing productivity gains are a key factor suppressing growth worldwide.
What no one can agree on is why this is happening. Some economists think traditional measures designed for manufacturing - heavy economies simply aren't detecting productivity gains in services, or the effect of newer, information - intensive technologies. There's also a natural lag between the introduction of new technologies and their full effect. It may simply be too soon to see productivity improvements.
Yet such factors have always been present to some degree; they'd also have affected earlier productivity estimates. The real issues are more fundamental - and intractable.