### 经济代写|宏观经济学代写Macroeconomics代考|ECON1120

statistics-lab™ 为您的留学生涯保驾护航 在代写宏观经济学Macroeconomics方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写宏观经济学Macroeconomics代写方面经验极为丰富，各种代写宏观经济学Macroeconomics相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 经济代写|宏观经济学代写Macroeconomics代考|The Shipbuilding Model and the Lambert Function

In his 1931 article on the “Shipbuilding cycle,” Tinbergen was interested in the increase of tonnage that followed the building of ships with a lag of about one year due to the construction period. From this connection a relation emerged between the increase of total tonnage and the volume of total tonnage two years before (Tinbergen, 1959: 2). Tinbergen proposed to model this relation as a differential equation with a delay, of the form:
$$\dot{f}(t)=-a f(t-\theta),$$
where $f(t)$ is the tonnage as a function of time, $\theta$ represents the delay between the tonnage and its increase in $t$, and $a$ is the intensity of the relation, the volume of increase above the trend (linbergen, 1959: 3). Tinbergen assumed a solution to his equation of the form $f(t)=C e^{\lambda t}$, which, inserted into the equation above yields $\lambda=-a e^{-\lambda \theta}$, once we have simplified the $C$ which only depends on the initial conditions. $\lambda$ can be a real or complex number, but because it appears both in the exponential function and alone this equation is transcendental. Now, “transcendental” means that usually the answer will only be found “experimentally” as Tinbergen put it. Indeed a transcendental equation is periodic, in the same sense that the exponential function with an imaginary argument traces a circle repeating itself as the argument increases. To find a general solution, Tinbergen (and after him Frisch and Kalecki) separated the real and the imaginary part of this equation and solved for one of the two in terms of trigonometric functions; for instance Tinbergen obtained the equation:
$$b \frac{\sin (y)}{y}=e^{-\frac{y}{\tan (y)}},$$
where $b=a \theta$ and $\lambda=x+i y, i=\sqrt{-1}$. To find the solutions for $y$ of this type of equations, they took the same approach of plotting both sides and looking for points of intersection, before improving on this solution with simple algorithms. Figure $2.4$ shows in the solid red lines the right hand side of the Eq. 2.2, while the dashed lines are the left hand side, for three different values of $b$ and both as a function of $y$.
It is readily apparent that there will be only one solution in each interval of length $2 \pi$. We can see that the leftmost solution will have the lowest frequency, that is, the largest period, and that all other solutions will have a higher frequency; thus the roots of the characteristic equation above will be ordered by their decreasing period or increasing frequency.

## 经济代写|宏观经济学代写Macroeconomics代考|From Natural Sciences to Economics

Hamburger claimed that it was only with new mathematical tools that economists would be able to account quantitatively and qualitatively for economic processes. Ultimately, the aim was to transform economics into a science similar to biology, ${ }^5$ a science capable of understanding the operation of social organisms beset by recurrent “pathologies.” It should be noted that Hamburger was not the only economist interested in business cycles who was showing some discontent with a mechanical analogy. Ernst Wagemann, the German head of the imperial statistical office and of the business cycle research institute of Berlin, in a book published in 1928, called as well for a biological metaphor.

Although Wagemann wrote in German, his book met enough success to warrant its translation in English only two years later under the title Economic Rhythm: A Theory of Business Cycles, with a prefatory note from Wesley C. Mitchell (Wagemann, 1930). In the preface to the English edition, Wagemann presented his contribution as a small step “toward the repayment of the debt which Europe owes to America in the field of research into economic dynamics” (Wagemann, 1930: v). However, the type of dynamics that was applied remained very empirical: although Wagemann was searching for a theory, he steered resolutely away from abstract constructions which were heavily criticized. His review of existing theories led him to propose that “while the American methods are those of engineering, and the Russian those of astronomy, the German institute represents the medical, or, better, the organicbiological point of view” (1930: 10). The “organic-biological principle” which he described (with reference to Menger) was meant to capture both the interconnection of the separate parts of an (economic) organism as well as “a peculiarity which may be defined as consisting in the power to regulate its own movement” (1930: 11), an approach which he emphasized as “anything but mechanical” (1930: 11).

Another radical opinion on the business cycle was that it was only a “myth.” This opinion was shared among American economists and statisticians, such as Carl Snyder (1930) and Irving Fisher (1925). ${ }^6$ While the former based his claim on the fact that compared to the growth of the economy, the amplitude of fluctuations remained within certain limits, the second doubted that “inherent” cyclical regularity in business could be detected. For Fisher, even if there existed a simple self-generating cycle similar to that of a pendulum swinging under the influence of the force of gravity, its tendency to materialize would be necessarily “defeated in practice” (Fisher, 1925: 192). To show this, he proposed to move away from the pendulum metaphor, toward the “physical analogue” of “the sway of the trees or of their branches.” For instance, after a tree is bended, one observes a swaying movement similar to that of the cycle: but Fisher did not think that such a movement was actually observed in the woods: “in actual experience […] twigs or tree tops seldom oscillate so regularly, even temporarily; they register instead, chiefly the variations in wind velocity” (Fisher, 1925: 192). A steady wind as well as any “outside forces”7 may thus bend the trees for weeks and annihilate completely their tendency to swing back and forth while changes in wind speed or in its direction will simply modify the angle of the tree with the ground.

# 宏观经济学代考

## 经济代写|宏观经济学代写Macroeconomics代考|The Shipbuilding Model and the Lambert Function

$$\dot{f}(t)=-a f(t-\theta),$$

$$b \frac{\sin (y)}{y}=e^{-\frac{y}{\tan (y)}},$$

## 经济代写|宏观经济学代写Macroeconomics代考|From Natural Sciences to Economics

Hamburger 声称，只有使用新的数学工具，经济学家才能对经济过程进行定量和定性分析。最终，目标 是将经济学转变为类似于生物学的科学， ${ }^5$ 一门能够理解被反复出现的”病态” 困扰的社会有机体运作的科 学。应该指出的是，汉堡并不是唯一对商业周期感兴趣并对机械类比表示不满的经济学家。德国帝国统 计局局长兼柏林商业周期研究所所长恩斯特. 瓦格曼 (Ernst Wagemann) 在 1928 年出版的一本书中也呼 吁使用生物学隐喻。

## 有限元方法代写

tatistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。