Estimación del valor del regadío a partir del precio de la tierra

In this paper, we estimate the value of irrigated land in the province of Leon (Spain) using land prices (irrigated and non irrigated) for two different uses (crop production and pasture) in ten different districts. The value of benefits associated with irrigation can be estimated by comparing the price of an irrigated plot of land with a similar plot of non irrigated land. The logical difficulty of finding these two similar (except for water) plots of land can be overcome using regression analysis where the effect of irrigation on land prices can be estimated after controlling for other differences in the plots of land analyzed. In the present paper, using an econometric model, we estimate the average prices associated with irrigated and non irrigated land. The difference among these average prices is an estimate of the value of irrigation. The results of this paper can be used in the analysis of new irrigation projects.

On a logical difficulty in the directed mutation debate

SummaryThis paper calls attention to an overlooked logical difficulty that has impeded the directed mutation debate for over half a century. It further suggests that the random mutation hypothesis be regarded at present as a null hypothesis in evolutionary biology.