The relevance of hedonic price indices

We argue that for the case of heterogeneous commodities with infrequent tradings, such as paintings, it is relevant to base a price index on hedonic regressions using all sales and not resales only. To support this conclusion we construct a price index for paintings by Impressionists and their followers and compare the various estimators using bootstrapping techniques. Copyright Kluwer Academic Publishers 1996price index, heterogeneous commodities, returns on art investment,

The costs of soil erosion

The aim of this study was a survey of the estimated costs of soil erosion, an issue of fundamental importance in view of the current worldwide discussions on sustainability. A list was drawn up of research papers on erosion (on-site and off-site effects) and their respective costs. The estimates indicate the amount of resources spent in the process of soil degradation, raising a general awareness of the need for soil conservation. On-site costs affect the production units directly, while off-site costs create a burden borne by the environment, economy and society. In addition, estimating the costs of soil erosion should be effective to alert the agricultural producers, society and government for the need for measures that can be implemented to bring erosion under control. Among the various estimates of soil erosion costs between 1933 a 2010, the highest figure was 45.5 billion dollars a year for the European Union. In the United States, the highest figure was 44 billion dollars a year. In Brazil, estimates for the state of Paraná indicate a value of 242 million dollars a year, and for the state of São Paulo, 212 million dollars a year. These figures show, above all, that conservation measures must be implemented if crop and livestock farming production are to be sustainable