concessional       
adjective  finance & economics specialized uk/kənˈseʃ.ən.əl/ us/kənˈseʃ.ən.əl/
 (价格,税率,资助等)优惠的
offered at a better rate than usual, for example at a lower rate of tax or a higher rate of an allowance
  The scheme allows the import of capital goods for export production at a concessional rate of duty. 该计划允许以优惠税率进口用于出口生产的资本货物。 
 Concessional loans are available to employees that meet conditions. 符合条件的员工可以获得优惠贷款。 
 Food aid is provided on concessional credit terms. 粮食援助以优惠信贷条款提供。 
 - More examples
 - Concessional pension contributions include deductible employer and self-employed contributions.
 - Any earnings you receive from super investments are taxed at a concessional rate of 15%, which is generally lower than other forms of savings.
 - There was considerable concessional lending to eastern Europe.
 - An employee may benefit from a concessional housing loan, supplementary health benefits or childcare support.
 - An environmental project could potentially obtain its entire project costs from concessional financing.