We consider some asymptotic distribution theory for M-estimators of the parameters of a linear model whose errors are non-negative; these estimators are the solutions of constrained optimization problems and their asymptotic theory is non-standard. Under weak conditions on the distribution of the...

Of water withdrawn for agricultural crop irrigation, a portion is consumed and the remainder comes back to the hydrologic system as return flows. Previous models of irrigation water demand have mostly focused on the change in withdrawals in response to price changes, even though knowledge of the...

Traditional approaches to estimating the potential benefits of water reform, including the introduction of water markets, have relied on short-run models which assume irrigation capital is either fixed or not a constraint on decision making. Other studies have incorporated a long-run decision...

In this paper the incremental values of water are calculated for irrigators in the Fish-Sundays Scheme of South Africa's Eastern Cape province. The socio-political pressure for redistribution of agricultural resources provided the imperative for this study. The model of the Fish-Sundays Scheme...

In this paper we use Lagrange interpolation polynomials to obtain good gradient estimations.This is e.g. important for nonlinear programming solvers.As an error criterion we take the mean squared error.This error can be split up into a deterministic and a stochastic error.We analyze these errors...

The aim of this work is to measure the Industrial Marshallian District (IMD) effect through non-radial measures of technical efficiency. Taking as reference the spatial location of each firm (inside or outside of the IMD), a valuable information can be obtained to assess whether there exist...