The result shows that , under the condition of perfect competition , if bank ' s costs of providing transaction services for customers are sufficiently small , then a small tax on deposits interest income does not affect the choice of depositors ( or investors ) between deposits and direct investment ; a business tax on bank loan interest income leads to tax incidence , thus raises loan rates and induces entrepreneurs to switch from bank loan to direct financing ; a tax on bank ' s income also raises the loan interest rate , and hence reduces the demand of loans 研究结果表明，在完全竞争条件下，当银行为客户提供的交易服务成本很低时，以较低的税率对储蓄利息开征利息所得税不会影响储户（或投资者）在储蓄和直接投资之间的选择；对银行贷款利息收入开征营业税，则会引起税收转嫁，提高贷款利息率，使部分企业选择直接融资方式而不是从银行贷款；银行业所得税也会提高贷款利率，减少贷款需求量。
