The purpose of this study is to investigate the relationship between a firm's R&D expenditures considered as an investment in knowledge, and its productivity, looking at sectoral peculiarities which may emerge; to this end, we use a large unique longitudinal database consisting of 1,809 US and...

The modern Air Navigation Service (ANS), also known as Air Traffic Control (ATC), is one of the largest networked socio-technical systems developed and operated by humankind. The ANS ensures safe and efficient flight operations 24 hours a day, 365 days a year across continents and oceans for...