In this paper, we study a notion of sufficient input, i.e. input that allows to produce at least one unit of output when the other inputs are fixed at any positive level. We show that such an input allows to produce any positive amount of production. The main property of sufficient inputs is as...

There is a large consensus among international institutions and national governments to favor urban-containment policies - the compact city - as a way to reduce the ecological footprint of cities. This approach overlooks the following basic trade-off: the concentration of activities decreases...