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\hypersetup{pdftitle={The Effect of International Prices on World Market Demand of Sudanese Gum Hashab Grades },pdfauthor={Yahia Omar Adam, Huda Abdelwahab Sharawi, Jürgen Pretzsch},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={Gum Hashab grades, price elasticity, world market demand         },pdfpagemode=None,colorlinks=true}
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\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 14-16, 2010, Zurich}}\\[1ex] \Large{``World Food System  ---\\A Contribution from Europe''\\[2ex]}}
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\Large{\textbf{The Effect of International Prices on World Market Demand of Sudanese Gum Hashab Grades \footnote{\textbf{Contact Address:} Yahia Omar Adam, Technische Universität Dresden, Institute of International Forestry and Forest Products, Pienner straße 7, 01737~Dresden , Germany, \mbox{e-mail}: \email{gumaa1973@hotmail.com}}\\[0.8ex]}}
\normalsize{\textsc{Yahia Omar Adam$^{1}$, Huda Abdelwahab Sharawi$^{2}$, Jürgen Pretzsch$^{1}$}}
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\begin{itemize*}
\item[]{\small{\textit{$^{1}$Technische Universität Dresden, Institute of International Forestry and Forest Products, Germany}}}
\item[]{\small{\textit{$^{2}$Khartoum University, Faculty of Forestry, Forest Management, Sudan}}}
\end{itemize*}
\index[author]{Omar Adam, Yahia}
\index[author]{Abdelwahab Sharawi, Huda}
\index[author]{Pretzsch, Jürgen}
\begin{center}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
Gum Hashab from (\textit{Acacia senegal} L.) has long been in international trade where Sudan was associated with this commodity and its producing trees. Almost all Sudanese gum Hashab is exported as a primary product to industrial countries, where the Sudan used to have a near monopoly position on the world market. In 1994 gum Hashab value addition was introduced to restore gum Hashab world market demand to its previous levels through gum processing. Although the gum value addition, the world markets demand continued to show a general declining trend over time. This study was conducted to analyse the effect of international prices on gum Hashab grades (cleaned, cleaned sifted and handpicked selected) world market demand. Specifically, the study attempted to develop and assess world market demand models for the gum Hashab grades, and estimate the price elasticity for the introduced grades in world market. Time series data for gum Hashab grade quantities exported and their international prices for the period 1970 to 2001 were collected from secondary sources. A world market demand models for gum Hashab grades were estimated, using OLS technique, and tested using various economic, statistic and econometric criteria. The results indicate that the cleaned, cleaned sifted and handpicked selected grades were relatively price inelastic (price elasticities of world market demand were 0.494, 0.465 and 0.367, respectively). The study concludes that gum Hashab grades world market demand acted differently, and that although the international market price was a factor influencing the gum grades world market demand but its effect not substantial and that other factors which are maybe having greater effect will require to be investigated.}

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\noindent \textbf{Keywords:} Gum Hashab grades, price elasticity, world market demand         
\index[key]{Gum Arabic!Hashab grades}
\index[key]{Price elasticity}
\index[key]{World market demand         }
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