哪位高手能指导下在windeap软件中用规模可变假设下的多阶段BCC模型分析保险公司效率的时候出现“Unbounded objective function”是怎么回事啊？结果如下图：

Results from DEAP Version 2.1

Instruction file = $$TEMP$$.INS
Data file          = $$TEMP$$.DTA

Input orientated DEA

Scale assumption: VRS

Slacks calculated using multi-stage method
Unbounded objective function
Unbounded objective function
Unbounded objective function
Unbounded objective function
Unbounded objective function
Unbounded objective function
Unbounded objective function
Unbounded objective function

EFFICIENCY SUMMARY:

  firm  crste  vrste  scale

    1  0.553  0.835  0.662 drs
    2  1.000  1.000  1.000  -
    3  0.125  0.138  0.907 irs
    4  0.496  1.000  0.496 drs
    5  0.339  1.000  0.339 drs
…………