Emissions of pollutants from motor vehicles have been the focus of longstanding concerns for both governments and the public at large because of their impact on air quality and human health. More recently, emissions of greenhouse gases have been of growing concern because of their impacts on...

Productivity is commonly defined as a ratio between the volume of output and the volume of inputs. In other words, it measures how efficiently production inputs, such as labour and capital, are being used in an economy to produce a given level of output. Broadly, productivity measures can be...