Abstract: The essence of the middleincome trap is that the income level correlate nonlinearly with its growth rates The Williamson turn point determines whether China would fall into the trap Based on the framework of spatial Gini coefficient, this paper applies spatial autocorrelation theory to quantify the contribution of implicit factors This paper also develops the model of middleincome trap based on the Williamson invertedU curve The results show that regional income gap has the relationship of invertedU with GDP per capita, or more precisely, that of Sshaped curve The results from the smooth transition regression model indicate that the current turnpoint is 4 18930 US dollar per capita China has already passed this point since 2005 However China has not entered a “high regime” path This paper suggests that China further implements the strategy of high starting point of regional harmonious development, forms a complete set of sound macroeconomic policies, with deepening the reform of income distribution system.

Key words: middleincome trap , regional Gini coefficient , Williamson invertedU curve , smooth transition regression model

摘要： “中等收入陷阱”在本质上是收入与增长非线性相关系，而威廉姆森拐点决定着中国经济发展是否落入“中等收入陷阱”的关键。本文基于空间自相关理论提出空间基尼系数的一个分解框架，并运用威廉姆森“倒U型”理论构建“中等收入陷阱”理论模型。结果表明：中国地区收入差距与人均GDP之间存在“倒U型”非线性关系，更确切地说是S型关系。以平滑转化回归模型测算，中国存在人均GDP为4 18930美元拐点，并于2005年越过拐点，但进入地区差距收敛的“高体制”路径仍有一定差距。因此，中国在政策应对上要进一步通过实施高起点的区域协调发展战略，健全宏观配套政策，配合深化收入分配体制改革，从而成功地跨越“中等收入陷阱”。

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