Marginal propensity to consume是怎么计算的，为什么不是0.65， 而是0.65/0.72

NO.PZ2023071902000016 问题如下 QuestionIn a theoreticeconomic mol, consumer spenng is 65% of pre-trevenue, anthe average taxation rate is 28% of the overall revenue. If forecastegovernment expentures are projecteto rise $1.5 billion, whamount, in billions, will the totrevenue anexpenture likely increase? A.$2.8. B.$4.3. C.$1.1. Solution Correct. The fiscmultiplier is 1 1− 1−T ) where c = marginpropensity to consume = consumption/sposable income T = the trate Assuming pre-tincome of $1 sposable income: $1× (1 – 0.28) = $0.72 Marginpropensity to consume: $0.65/$0.72 = 0.9028 The fiscmultiplier: 1/[1 – 0.9028(1 – 0.28)] = 2.8571 With increase in government expentures of $1.5 billion, totrevenues anexpentures will ascen$1.5billion × 2.8571 ≈ $4.3 billion FiscPolicy• scritools of fiscpolicy, inclung their aantages ansaantages 依据乘数公式，假设税前收入为1美元可支配收入:1美元×(1 - 0.28) = 0.72美元边际消费倾向:0.65/ 0.72 = 0.9028财政乘数:1/[1 - 0.9028(1 - 0.28)]= 2.8571财政支出增加15亿美元，收支总额将增加15亿美元× 28.571≈43亿美元 这里为什么不是1/(1-0.65(1-28%))

NO.PZ2023071902000016 问题如下 QuestionIn a theoreticeconomic mol, consumer spenng is 65% of pre-trevenue, anthe average taxation rate is 28% of the overall revenue. If forecastegovernment expentures are projecteto rise $1.5 billion, whamount, in billions, will the totrevenue anexpenture likely increase? A.$2.8. B.$4.3. C.$1.1. Solution Correct. The fiscmultiplier is 1 1− 1−T ) where c = marginpropensity to consume = consumption/sposable income T = the trate Assuming pre-tincome of $1 sposable income: $1× (1 – 0.28) = $0.72 Marginpropensity to consume: $0.65/$0.72 = 0.9028 The fiscmultiplier: 1/[1 – 0.9028(1 – 0.28)] = 2.8571 With increase in government expentures of $1.5 billion, totrevenues anexpentures will ascen$1.5billion × 2.8571 ≈ $4.3 billion FiscPolicy• scritools of fiscpolicy, inclung their aantages ansaantages 依据乘数公式，假设税前收入为1美元可支配收入:1美元×(1 - 0.28) = 0.72美元边际消费倾向:0.65/ 0.72 = 0.9028财政乘数:1/[1 - 0.9028(1 - 0.28)]= 2.8571财政支出增加15亿美元，收支总额将增加15亿美元× 28.571≈43亿美元 marginpropensity to consume 消费 / 收入（1-税率）财政乘数 = 1/(1 + C * （1-税率）)那这个公式先除个（1-税率），再乘回来折腾啥呢，不直接 1/ (1 + consumer spenng is 65%)完事儿，这不简洁多了？

NO.PZ2023071902000016问题如下 QuestionIn a theoreticeconomic mol, consumer spenng is 65% of pre-trevenue, anthe average taxation rate is 28% of the overall revenue. If forecastegovernment expentures are projecteto rise $1.5 billion, whamount, in billions, will the totrevenue anexpenture likely increase? A.$2.8.B.$4.3.C.$1.1. Solution Correct. The fiscmultiplier is 1 1− 1−T ) where c = marginpropensity to consume = consumption/sposable income T = the trate Assuming pre-tincome of $1 sposable income: $1× (1 – 0.28) = $0.72 Marginpropensity to consume: $0.65/$0.72 = 0.9028 The fiscmultiplier: 1/[1 – 0.9028(1 – 0.28)] = 2.8571 With increase in government expentures of $1.5 billion, totrevenues anexpentures will ascen$1.5billion × 2.8571 ≈ $4.3 billion FiscPolicy• scritools of fiscpolicy, inclung their aantages ansaantages 没太明白答案解析是什么意思