Enhancing Irrigation Efficiency but Increasing Water Use: The Jevons' Paradox

In this paper we analyze the conditions under which increasing technical efficiency of water use in the agricultural sector might not reduce water demand and pressures on water ecosystems. Departing from this basic problem we discuss how policy measures performed to enhance water productivity in the agriculture might be transformed into effective alternatives to improve the conservation of water resources and then guarantee the successful implementation of the Water Framework Directive. A preference revelation model is presented in the third section of the paper and one empirical application to an irrigation district in southern Spain is used in the fourth section to discuss the effectiveness of water savings measures.Water Framework Directive, Water Economics, Agricultural Economics, Simulation Models, Preference Revelation., Resource /Energy Economics and Policy,

The Implicit Function Theorem for continuous functions

In the present paper we obtain a new homological version of the implicit function theorem and some versions of the Darboux theorem. Such results are proved for continuous maps on topological manifolds. As a consequence, some versions of these classic theorems are proved when we consider differenciable (not necessarily C^1) maps.Comment: 9 pages, no figure

Firm Entry, Productivity Differentials and Turnovers in Import Substituting Markets: A study of the petrochemical industry in Colombia

This paper analyses plant entry, total factor productivity growth, average productivity level differentials and turnovers across Colombia's petrochemical industry for the 1974-1998 period. Results show that successful entrants shaped industry productivity and induced plant restructuring among incumbent plants. There is consistent plant heterogeneity across plant cohorts as well as across sub-markets within petrochemicals. Entry flows were steady increasing within plastics regardless of trade policy regimes. Survival rates are remarkably high and consistent over time in medium-size plants meaning that entrants adopted competitive post-entry strategies. Total factor productivity growth decomposition shows that the incumbent effect dominates the turnover effect. Market share reallocation among continuing plants constitutes an important source of productivity growth. Econometric results suggest that barriers to entry associated with plant technology licensing and dependence of imported raw materials deter entry while complementary market variables such as industry productivity levels, growth in housing construction, and fringe competition induce firm entry.Entry, Turnover, Total Factor Productivity, Petrochemical Industry