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The use of weather derivatives is impaired with a basis risk which diminishes the hedging effectiveness and hinders the distribution of these risk management instruments in the agricultural sector. A frequently suggested approach to reduce the basis risk is the use of mixed indices composed of several weather variables. The purpose of this paper is to compare the hedging effectiveness of a simple temperature‐based and a simple precipitation‐based weather derivative with that of a derivative based on a mixed index of two weather variables.

The basis of this comparison are empirical yield time series of the winter wheat production of 32 farms located in central Germany, as well as daily temperature and precipitation data collected by selected weather stations over several years. Insurance is structured as an option on an accumulated weather index and priced by index‐value simulation. In addition, the bootstrapping method is used to improve statistical reliability. The hedging effectiveness is measured non‐parametrically regarding the relative reduction of the standard deviation of winter wheat revenues caused by using weather derivatives.

The results reveal that mixed index‐based weather derivatives have a significantly higher potential to reduce the risk of winter wheat revenues than simple index‐based weather derivatives. However, using mixed index‐based weather derivatives does not lead to a significantly higher hedging effectiveness than the simultaneous use of several simple index‐based weather derivatives. Moreover, simple index‐based weather derivatives may more easily raise the interest of other industries which could serve as potential trading partners for the agricultural sector.

The authors analyzed the hedging effectiveness of weather derivatives based on simple and mixed indices with regard to the production of winter wheat in Central Germany. To confirm that the present results are generalizable, further research is required for other types of production apart from winter wheat cultivation and with respect to other regions besides Germany.

The focus and results of the present study are very relevant for farmers as well as for potential providers of weather derivatives. The results reconfirm that weather derivative providers should better offer different weather derivatives based on a simple index than complex derivatives that are based on a mixed index.

To the best of the authors' knowledge, this paper is the first that provides a comparative impact analysis of simple and mixed index‐based weather derivatives conducted for real individual farms with regard to their hedging effectiveness.

This article reviews the state of the art in automatic indexing, that is, automatic techniques for analysing and characterising documents, for manipulating their descriptions in searching, and for generating the index language used for these purposes. It concentrates on the literature from 1968 to 1973. Section I defines the topic and its context. Sections II and III consider work in syntax and semantics respectively in detail. Section IV comments on ‘indirect’ indexing. Section V briefly surveys operating mechanized systems. In Section VI major experiments in automatic indexing are reviewed, and Section VII attempts an overall conclusion on the current state of automatic indexing techniques.

This chapter builds monthly time-series of Divisia monetary aggregates for the Gulf area for the period of June 2004 to December 2011, using area-wide data. We also offer an “economic stability” indicator for the Gulf Cooperation Council (GCC) area by analyzing the dynamics pertaining to certain variables such as the dual price aggregates, aggregate interest rates, and the Divisia aggregate user-cost growth rates. Our findings unfold the superiority of the Divisia indexes over the officially published simple-sum monetary aggregates in monitoring the business cycles. There is also direct evidence on higher economic harmonization between GCC countries – especially in terms of their financial markets and the monetary policy. Monetary policy often uses interest rate rules, when the economy is subject only to technology shocks. In that case, money is nevertheless relevant as an endogenous indicator (Woodford, M. (2003). Interest and prices: Foundations of a theory of monetary policy. Princeton, NJ: Princeton University Press.). Properly weighted monetary aggregates provide critical information to policy-makers regarding inside liquidity created by financial intermediaries. In addition, policy rules should include money as well as interest rates, when the economy is subject to monetary shocks as well as technology shocks. The data show narrow aggregates growing while broad aggregates collapsed following the financial crises. This information clearly signals problems with the financial system's ability to create liquidity during the crises.

This paper describes a simple method for developing a list of core serials in a particular subject field by analysing article citations in electronic indexes. The Simple Index Method overcomes the difficulties in building a core list for serials in interdisciplinary fields by using multiple indexes which cover various aspects of the subject. This method permits the collection development librarian to develop a core list when standard bibliographies or specific indexing and abstracting tools are lacking and to tailor that list to the needs of the local situation.