Productivity versus EfficiencyOne of the reasons I feel the need to define things here before talking about them is that people love to take terms and twist them to mean whatever is most convenient.
Under its original economic definition, productivity is a synonym of efficiency: getting more done with the same amount of resources. Classic productivity was hard to achieve, so people craftily and unconsciously morphed the word into something that was a more easily attainable goal. Instead of efficiency, which was what being productivity used to mean, people just started using the term to refer to getting things done in general.
Usually when I hear people use the term productivity these days, they use it to refer to the fact that they got a lot done in a day or how busy they feel. I'm going to adopt this modified definition of productivity:
Productivity: The amount of rewards generated in a particular span of time, regardless of how efficiently those rewards were generated or how much effort and resources they cost.A great example of productivity and efficiency together is an automated factory. However, since productivity is an equation, it's possible to be productive without being efficient, as well as to be efficient without being productive. People who follow The 4-hour Workweek and other such methods attempt to get the same amount of rewards for much less effort, through increased efficiency.
Productivity = (Effort x Efficiency)/Diminishing returns
On the other end of the spectrum, it's much more common to find productivity without efficiency. I used to work 16 hour days and 7 day weeks. I got a huge amount of work done, but work was all I ever did. I was being very productive, but at a huge cost. Therefore my efficiency was very low.