Virgin nature, as well as historical and cultural monuments located in National Parks, all form part of our national heritage. Tourism and recre- ation allow visitors to National Parks to enjoy nature, to reinstate, recover and broaden their personal outlook, to experience local history,...

This paper deals with a control theory approach to stabilize cyclical price movements. Firstly, we pursue a welfare economist’s approach, delineating a public objective function derived from consumer and producer surplus as well as trade budget at world market price. Trade is a con¬trol...