A few decades ago rubber was one of the first tree crops to be characterized by a spectacular breakthrough, the production of new, highly productive clonal material. With regard to rubber, the adoption of clonal planting materials led to a spectacular improvement in labour-productivity and...

This paper helps understand the increasing popularity of a new type of contract in the smallholder plantation economy in Ivory Coast : the ?Plant and Share? arrangement. This contract, based on a partnership between autochthons and migrants, provides evidence for the capacity for institutional...

[eng] The author makes an analysis of the social stratification of different ethnic groups induced by the plantation economy. During the «mining period», land and labour seem equally important. The «allochthonous» consider labour supply as crucial for settlement and land extension...

The most traditional and widely used farming systems in the humid upland tropics are based on fallowing and various forms of slash-and-burn agriculture. Their sustainability depends on the duration of the fallow; as long as the fallow stage is longer than seven or eight years, slash-and-burn...

Effects connected with the world globalization affect also the financial markets. On a way towards quantifying the related characteristics we study the financial empirical correlation matrix of the 60 companies which both the Deutsche Aktienindex (DAX) and the Dow Jones (DJ) industrial average...

A novel application of the correlation matrix formalism to study dynamics of the financial evolution is presented. This formalism allows to quantify the memory effects as well as some potential repeatable intradaily structures in the financial time-series. The present study is based on the...

The correlation matrix formalism is used to study temporal aspects of the stock market evolution. This formalism allows to decompose the financial dynamics into noise as well as into some coherent repeatable intraday structures. The present study is based on the high-frequency Deutsche...

Financial empirical correlation matrices of all the companies which both, the Deutsche Aktienindex (DAX) and the Dow Jones comprised during the time period 1990-1999 are studied using a time window of a limited, either 30 or 60, number of trading days. This allows a clear identification of the...

Detailed study of the financial empirical correlation matrix of the 30 companies comprised by DAX within the period of the last 11 years, using the time-window of 30 trading days, is presented. This allows to clearly identify a nontrivial time-dependence of the resulting correlations. In...