Zhejiang's main manufacturing sectors are electromechanical industries, textiles, chemical industries, food, and construction materials. In recent years Zhejiang has followed its own development model, dubbed the "Zhejiang model", which is based on prioritizing and encouraging entrepreneurship, an emphasis on small businesses responsive to the whims of the market, large public investments into infrastructure, and the production of low-cost goods in bulk for both domestic consumption and export. As a result, Zhejiang has made itself one of the richest provinces, and the "Zhejiang spirit" has become something of a legend within China. However, some economists now worry that this model is not sustainable, in that it is inefficient and places unreasonable demands on raw materials and public utilities, and also a dead end, in that the myriad small businesses in Zhejiang producing cheap goods in bulk are unable to move to more sophisticated or technologically more advanced industries. The economic heart of Zhejiang is moving from North Zhejiang, centered on Hangzhou, southeastward to the region centered on Wenzhou and Taizhou. The per capita disposable income of urbanites in Zhejiang reached 24,611 yuan (US$3,603) in 2009, an annual real growth of 8.3%. The per capita pure income of rural residents stood at 10,007 yuan (US$1,465), a real growth of 8.1% year-on-year. Zhejiang's nominal GDP for 2011 was 3.20 trillion yuan (US$506 billion) with a per capita GDP of 44,335 yuan (US$6,490). In 2009, Zhejiang's primary, secondary, and tertiary industries were worth 116.2 billion yuan (US$17 billion), 1.1843 trillion yuan (US$173.4 billion), and 982.7 billion yuan (US$143.9 billion) respectively.
What is Zhejiang's own development model not considered? (If the question is unanswerable, say "unanswerable")
unanswerable