A 1992 Social Accounting Matrix (SAM) for Tanzania

This paper documents the construction of a 1992 social accounting matrix (SAM) for Tanzania. On the basis of recently generated national accounts data, a 56-sector SAM is built focusing on the disaggregation of agriculture — which comprises 21 of the 56 sectors. First, a highly aggregated SAM (macrosam) is designed to set the macroeconomic framework that provides the control totals for the disaggregation procedure. Then, the sector disaggregation of the microeconomic SAM (microsam) is done. Data sources and the data adjustments made are presented. The microsam differentiates 4 household types and 5 labor categories. Special features of the microsam include non-monetary, own-household consumption and separate marketing margins on domestic products, exports, and imports — which play a crucial role in the low income economies of sub-Saharan Africa. Since the data base is to be used for economic policy modeling, consideration of these features will have a significant influence on the results of the analysis. Due to data insufficiencies the first microsam obtained from adjusted raw data (protosam) is highly unbalanced. A cross-entropy estimation method is applied to balance the protosam and generate the final estimated 1992 microsam for Tanzania that uses all available information in a consistent framework.

本文详述了坦桑尼亚1992年社会核算矩阵（Social Accounting Matrix, SAM）的构建过程。本文基于最新编制的国民账户数据，搭建了一个包含56个部门的SAM，重点对农业部门进行细分——农业部门占全部56个部门中的21个。首先，本文设计了高度汇总型社会核算矩阵（macrosam），以此搭建宏观经济框架，为后续的部门细分流程提供控制总量基准。随后完成微观经济SAM（microsam）的部门细分工作。本文还列出了所用的数据来源及所开展的数据调整工作。该微观SAM区分了4类家庭与5类劳动力群体。该微观SAM的特色之处包含非货币性的家庭自给消费，以及针对国内产品、出口品与进口品分别设置的营销价差——这类设置在撒哈拉以南非洲的低收入经济体中发挥着关键作用。由于该数据集将用于经济政策建模，对上述特征的考量将对分析结果产生显著影响。受限于数据不足，从调整后的原始数据中得到的首个微观SAM（protosam）存在严重的失衡问题。本文采用交叉熵估计方法对该protosam进行平衡修正，最终生成符合一致化分析框架、整合全部可用信息的坦桑尼亚1992年最终估计版微观SAM。