双语教学比赛讲稿：窦祥铭,安徽财经大学 经济学院

第一篇：双语教学比赛讲稿：窦祥铭,安徽财经大学 经济学院

Good afternoon, honorable judges, ladies and gentlemen, my name is Dou Xiangming, I come from the school of economics, today it is my greatest honor to have this opportunity to exchange my teaching experience with all of you here, and I wish to get your criticism and correction sincerely, thank you.In today’s class, we start to learn the fourth chapter: consumption and saving.消费和储蓄作为重要的宏观经济变量，它们对宏观经济的整体运行具有重要的影响，因此对它们的分析和学习具有极为重要的理论及现实意义。

The chapter is divided by 2 sections.The first section includes consumption, and the consumption function and the propensity to consume.The second section includes saving, the saving function, and the propensity to save.我们先来看关于消费的内容。First of all, it’s the definition of consumption.In macroeconomics, consumption refers to a country or a region’s individual residence or family’s all expenditures on purchasing consumer goods and services in order to satisfy consuming desire in a fixed time.显然，宏观经济学中的消费指的是总的消费。

Then, it’s the consumption function.The consumption function refers to the interdependent relationship between consumption and various factors that decide consumption.There are many factors influence consumption, such as the income level, the consumer price level, individual consumer ’s preference, consumer’s expectation of future income, consumer credit and it’s interest rate, etc, there is no doubt that the income level is the most important factor that influences consumption.消费函数指的是消费与决定消费的各种因素之间的相互依存的关系。影响消费的因素众多，比如收入水平、消费品价格水平、消费者个人偏好、消费者对未来收入的预期、消费信贷及其利率等，但毫无疑问其中影响消费最重要的一个因素是收入水平。宏观经济学初级阶段我们所学习的消费函数其实主要考虑的就2个因素，即作为自变量的收入水平和作为因变量的消费水平。

为更好地理解消费函数，我们有必要对消费函数的表达式及其图像展开学习。首先来看消费函数的一般表达式及其图像。In the graph above, vertical axis expresses the consumption level or C, horizontal axis expresses the income level or Y, we can see the consumption function curve slopes upward and becomes flatter.可见，图像中的消费函数曲线是一条向右上方倾斜且愈发平缓的曲线，这条曲线很明显地把消费函数的两个重要属性表示出来：一是随着收入的增加，消费也会增加，用数学语言表示就是一阶导数大于0；二是随着收入的增加，消费增加的速率会下降，用数学语言表示就是二阶导数小于0。

接着我们来看消费函数的线性表达式及其图像。In liner expression of the consumption function, a is the autonomous consumption, bY is the induced consumption, b is the marginal propensity to consume.在消费函数的线性表达式中，a是自发性消费，即不受收入影响而相对稳定的消费；bY是诱致性消费，即会受收入影响而相对不稳定的消费；b是边际消费倾向，还原为通俗语言，即每增加一个单位的收入，你会从中拿出多大的份额去用于消费。

边际消费倾向不同国家之间的差异较大，其中的原因是多方面，在此我就不再给予赘述。如曾经一段时间中国的边际消费倾向介于0.60—0.65之间，而同期美国的边际消费倾向却介于0.90—0.95之间。可见，中国人的边际消费倾向大大小于美国人的边际消费倾向，换言之，就是中国人更不愿意花钱。中国人花钱少，储蓄就高，短期看不利于市场的发展，但中长期看却能为社会扩大再生产积累起雄厚的资金；而美国人花钱多，储蓄就低，短期看能带动市场的发展，但中长期看却会造成社会扩大再生产资金的不足。中国把通过高储蓄积累起来的资金借给美国，因此成为目前美国最大的债主。

Finally, it’s the propensity to consume.The propensity to consume refers to the ratio of consumption to income, mainly including the average propensity to consume and the marginal propensity to consume.The average propensity to consume or APC refers to the ratio of total consumption to total income.根据定义，显然有平均消费倾向APC = C / Y。The marginal propensity to consume or MPC refers to the ratio of consumption increment to income increment.根据定义，显然有边际消费倾向MPC=ΔC/ΔY , 当ΔC和ΔY趋向于极小值时，MPC= dC/dY。通过简单的推导，我们能得出平均消费倾向APC＞边际消费倾向MPC，具体推导过程我就不写了，作为作业留给大家课下完成。

下面我们来看关于储蓄的内容。Similar with consumption, first of all, it’s the definition of saving.In macroeconomics, saving refers to a country or a region’s individual residence or family’s all income that excludes the consumption in a fixed time.根据定义，宏观经济学中的消费强调的也是总的消费。中国国民储蓄率很高，并且增长很快，传统观点认为主要原因在于中国的老百姓爱存钱，这点不假，但造成中国国民储蓄率高的真正原因却是相比老百姓，政府和企业更喜欢存钱，如1992—2012年，中国国民储蓄率从35%上升到59%，但居民储蓄率却一直维持在20%的水平，可见，政府和企业对储蓄更是“情有独钟”。

Then, it’s the saving function.The saving function refers to the interdependent relationship between saving and various factors that decide saving.There are many factors influence saving, such as the income level, wealth distribution, consuming habit, the structure of social security system, interest rate level, etc, there is no doubt that the income level is the most important factor that influences saving.储蓄函数指的是储蓄与决定储蓄的各种因素之 间的关系。影响消费的因素众多，如收入水平、财富分配状况、消费习惯、社会保障体系的结构、利率水平等，但其中最重要的一个因素还是收入水平。

和消费函数的学习一样，下面我们来学习储蓄函数的表达式及其图像。首先是储蓄函数的一般表达式及其图像。In the graph above, we can see the saving function curve slopes upward and becomes steeper.可见，图像中的储蓄函数曲线是一条向右上方倾斜且愈发陡峭的一条曲线，这条曲线很明显地把储蓄函数的两个重要属性表示出来：一是随着收入的增加，储蓄也会增加，用数学语言表示就是一阶导数大于0；二是随着收入的增加，储蓄增加的速率会加大，用数学语言表示就是二阶导数也大于0。

接着我们来看储蓄函数的线性表达式及其图像。In liner expression of the saving function,-a(minus a)is the autonomous saving,(1-b)Y(one minus b then times Y)is the induced saving, 1-b(one minus b)is the marginal propensity to save.在储蓄函数的线性表达式中，-a是自发性储蓄；(1-b)Y是诱致性储蓄；1-b是边际储蓄倾向。结合前面关于消费函数的学习，我们能看出储蓄函数与消费函数之间存在互补的关系，即知道其中一个函数，我们就能推出另外一个函数。

Finally, it’s the propensity to save.The propensity to save refers to the ratio of saving to income, mainly including the average propensity to save and the marginal propensity to save.The average propensity to save or APS refers to the ratio of total saving to total income.根据定义，显然有平均储蓄倾向APS = S / Y.The marginal propensity to save or MPS refers to the ratio of saving increment to income increment.根据定义，显然有边际储蓄倾向MPS=ΔS/ΔY , 当ΔS和ΔY趋向于极小值时，MPS= dS/dY。通过简单的推导，我们能得出平均储蓄倾向APS＜ 边际储蓄倾向MPS，具体推导过程也是今天我留给大家的课下作业。

In the end, it’s the Chapter Summary 1.In macroeconomics, consumption or saving focus on the aggregate consumption or saving.（在宏观经济学中，消费或储蓄强调的是总的消费或总的储蓄。）

2.The income level is the most important factor that decides consumption or saving.（收入水平是影响消费和投资的最重要的一个因素。）

3.There is a complementary relationship between the consumption function and the saving function.（消费函数和储蓄函数存在互补关系。）

4.APC﹥（is greater than）MPC, APS﹤（is lesser than）MPS, APC+(plus)APS=(equals)MPC+MPS=1.That is all, than you for your time and attention, see you next time, bye.