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What is man? 2017-09-25 06:12:56

Man means hand, such as in manual, manicure, manner, manufacture, manipulate, manager. Hand is really what distinguishes man from other animals. The densities of nerves around the human hands are very high. Active hand activities are what keep us healthy and agile. Most of us probably don’t spend enough time working our hands.



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相似的单词,不同的意思 2017-09-20 07:32:46

Similar words, different meanings


Some words have similar forms in French and English.But their meanings can be very different. Exploiter in French means operate in English. Pain in French means bread. Poisson in French means fish. Gras in French means fat. Ail in French means garlic. Lisent in French means read. These words often have opposite meanings in French and English.


These words indicate that the ancestors of French are more powerful than the ancestors of English. A certain action, which is normal operation for ancient French, is exploitation for ancient English. When ancient French were eating bread, it was painful for hungry ancient English to look on. In general, observing the lifestyle of the affluent is very painful for the poor. When ancient French and ancient English were together, French read out the orders and English listen. 


The differences in meaning of the two languages show that when two groups are of different status, it is impossible to have the same perspective. 






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为什么鱼比肉更容易煮熟? 2017-09-06 09:45:56

Why it takes shorter time to cook fish than meat?


It seems like it takes shorter time to cook fish than meat. Why is that?


Fish live in water. Fish's density is roughly the same as water. It takes less effort to support their weight in water than animals support their weight on land. Probably due to this, fish's flesh is not as tightly glued together as animal meat. That is why fish's flesh is easier to break down by cooking heat than the land animals' flesh.


Is that a reasonable guess?







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小米和 millet 2017-08-30 08:06:02

小米的英语是 millet. Let 是小的意思,比如,piglet 是小猪, booklet 是小册子。millet,就是小 mi, 或者小米。英语和汉语的结构,非常类似。


我说的,有没有一点道理?




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怎样计算股票的融资成本和预期回报? 2017-08-28 11:52:11

How to calculate the cost of equity or the expected rate of return of equity

What would be the proper way to calculate the cost of equity, or the expected rate of return of equity? There are at least two ways to calculate the cost of equity: Discounted Cash Flows (DCF) and CAPM. Do they provide similar values?  We will calculate the cost of equity by using historical data provided in Fama and French’s 2002 paper The Equity Premium.

Some relevant data are summarized in the following table (extracted from Table I of Fama and French (2002)).  All data are inflation adjusted.


Inflation rate

Dividend ratio

Dividend growth rate

Cost of equity from DCF (summation of  two previous columns)

Average S&P return

1872-1950

0.99

5.34

2.74

8.08

8.30

1951-2000

4.00

3.70

1.05

4.75

9.62

From 1872 to1950, cost of equity of the whole equity market calculated from DCF is 8.08% and cost of equity of the whole market from CAPM is 8.30%. They are pretty close.From 1951 to 2000, cost of equity of the whole equity market calculated from DCFis 4.75% and cost of equity of the whole market from CAPM is 9.62%. The annual difference is almost 5%. The results from the two methods are very different.

In our estimation of cost of equity or future expected return of equity,  which method and which result we shall rely on? DCF is a simpler method. It relies more on observable quantities.Personally, I feel DCF provides a more accurate result. But CAPM is a more prestigious theory in finance. If DCF provides more accurate results in the future, it will generate more questions about the validity of CAPM theory.

We will look further at the 1951-2000 data. In this period, the average economic return of the US businesses is 4.75%. But the financial return from holding the same businesses is 9.62%, which more than double the economic return. What is phenomenon indicate? Can this phenomenon last for long?






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一篇关于The Unity of Science and Economics 的评论 2017-08-25 19:49:33

A Review of The Unity of Science and Economics: A New Foundation of Economic Theory

By Dick_Burkhart on November 30, 2016


This short book outlines a new anduseful way of thinking about economics, based on measurable quantities, notutilities. These quantities are fixed costs of production, variable costs, rateof return, coefficient of uncertainty or risk, price, and quantity producedover a period of time. Under realistic assumptions, these factors are relatedby a second order linear partial differential equation that is a variant of theBlack-Scholes equation. This equation predicts a variety of economic behaviorthat poses difficulties for neoclassical theory. Examples are how economies ofscale give way to diminishing returns as output is increased, and how monetarypolicy magnifies business cycles.

Chen’s principle focus is on fixed costs versusvariable costs, noting the similarity between biological and economic systems.In a stable environment with abundant resources, large systems with high fixedcosts tend to dominate, because they are more efficient. But for fast changingor innovative systems, elaborate structures which optimize production are soonobsolete, so it is better to start with low fixed costs and put a lot more intoadaptation (= variable costs). Chen even applies this paradigm to languages(stable Chinese versus adaptive English) and to climax versus pioneer speciesin biology. He deviates to expound his entropy theory of value, versus utilitytheory or alternatives like labor theory or energy theory.

Chen’s theory is not comprehensive but is a good start.He includes many interesting and insightful remarks on current economics, bu the could have used a good proof reader, as many words are missing their finals’s. Also, his entropy theory of value is quite sketchy, though sensible at avery basic level. He admits that it must be qualified by a host of practicalconsiderations like monopoly power and other institutional practices, but hedoes not indicate how to model these effects. Personally, I find that theclosely related energy theory of value, or “net energy”, as developed byCharles Hall, is much more intuitive, since highly concentrated andtransportable energy, like oil, is the most useful form of the low entropy materialthat has high value under Chen’s theory. Incidentally, by “value” he meansprice, that is, Marx’s exchange value, not use value. This is an extremelyimportant distinction since fresh air has infinite use value to us but itsprice is zero. This distinction is the reason for “externalities” intraditional economics. A comprehensive theory must internalize use value, so Ihope that he will address this in his future work.

But I like Chen’s point of view on efficiency. Heavy investment to optimize a system or product may be counter productive when thesituation is in flux. In this case, low fixed costs and high variable costs maybe the name of the game, as with start ups. Of course, this only works when theexpected profits are high. Note that in general optimization yields complexity,such as filling every nook and cranny according to its local micro-environment,or the exact needs of each customer. From this point of view, traditionalfactories are very suboptimal – they take advantage of economies of scale butnot of diverse market opportunities when the means of production are moreflexible (via advanced computers and robots, fixed costs which are declining) .

However I take issue when Chen suggests (p. 55) that society can no longer afford as much investment in things with longer duration and high fixed cost, so we need to be thinking about less higher education and longer working lives. Here he totally misses the boat, because US society has already been investing far less in myriad ways, such as for infrastructure and in wages and benefits for most of the 99%. And this has happened while using the steady, if not spectacular, increase in GDP to dramatically increase investments in the affluent and things that serve them. So we know that substantial resources are present, at least for now, to invest for the benefit of future generations, but they are being wasted and misallocated to an extreme extent due to the greed and power of the 1%.

In fact I view that last 35 years of class warfare of the 1% against the 99% as one of the most successful in the history of the world, with pay for the bottom half the population stagnating or declining,when average pay should have increased by around ¾ in real dollars as measured by chained GDP per capita. Only the compensation of the 1% has kept pace with productivity, with all the gains going to the upper echelons of the 1%.

While Chen does address inequality, he asserts that increasing inequality is more efficient and utilizes higher fixed costs (p.32). In reality the higher fixed costs and lower prices primarily benefit the affluent, not the majority, who experience disinvestment and inadequate income to maintain their standard of living, despite lower prices for some things.This explains the vote for Donald Trump, with the majority hard hit by the rising costs of housing, health care, higher education, and other disparities,while the 1% revel in luxuries undreamed of by even the richest and most corrupt rulers of centuries past.

In theory this would be easy to fix. All we need are strongly progressive income and wealth taxes, together with strong regulation and enforcement, combined with universal ownership of the means of production,as suggested by Peter Barnes (“With Liberty and Dividends for All”). In practice,this will be extremely difficult due to the escalating political stresses created by mounting inequality documented by Peter Turchin (“Ages of Discord”).In addition, it is doubtful that the current US surplus will last much longer–that expanding ecological overshoot and turmoil will be followed by some formof collapse as the current global economic stagnation gradually gives way to resource-led contraction, despite technological progress. I’d love to see Professor Chen turn his mathematical acumen to these problems.

The link to the original review

https://www.amazon.com/Unity-Science-Economics-Foundation-Economic/product-reviews/1493934643

 



















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数学及其在社会科学中的应用 2017-08-25 09:45:53

Mathematics and its application to social sciences

Mathematics has played a fundamental role in understanding and forecasting nature's events. For example, mathematical models can generate more accurate weather forecasting than experienced human experts. Today, weather forecasting is made by computed results from mathematical models and not by committees of experts.

However, this is not the case in the social field. Rarely, important decisions on economic policy, population policy and other social policies are based on computed results of mathematical models. Mathematical models mostly are generated to give an aura of sophistication in social science.


A notable exception is the field of financial engineering. In this field,mathematical models are built on observable quantities. They usually generate more precise quantitative results than qualitative thinking. Today, many trading and risk management decisions in the financial institutions are based on mathematical models. Mathematicians have made great contributions in this field. Ed Thorp, a math professor for many years, is often called the father of quantitative investment. Fischer Black, a Ph.D. in mathematics, was the main founder of financial engineering. Many math graduates find their talents highly valued in the financial industry. Financial mathematics programs are established in many math departments to broaden the career opportunities for math students. 


There is a criticism that these mathematical models, while enriching financial institutions, cause great damages to the general society. But this criticism reveals that these mathematical models do provide benefit to the financial industry, sometimes at the cost of broader society. Can the benefits from the mathematical theories of financial engineering be extended to broader community?

From the early days of the financial engineering, there is an expectation that the theory developed in this field could be a part of the general advance in economic theory. Fischer Black, the main founder of financial engineering, once stated,

I like the beauty and symmetry in Mr. Treynor's equilibrium models so much that I started designing them myself. I worked on models in several areas:

Monetary theory

Business cycles

Options and warrants

For 20 years, I have been struggling to show people the beauty in these models to pass on knowledge I received from Mr. Treynor.

In monetary theory --- the theory of how money is related to economic activity --- I am still struggling. In business cycle theory --- the theory of fluctuation in the economy --- I am still struggling. In options and warrants, though, people see the beauty.

Black's comments show that he, as well as many others,sensed the close relations among different economic and financial problems. His comments also show that it is not always easy to extend an idea from one field to another field, even this might look straight forward with the benefit of hindsight.

I tried to understand life systems from the thermodynamic laws since I was an undergraduate student. I hope to develop a mathematical theory of life systems parallel to classical mechanics as a mathematical theory of general systems. I read about many existing theories, such as Prigogine's theory. However, these theories do not model life processes directly. For a long time, I had little idea how to develop such a theory. I only knew that thermodynamic processes are represented by partial differential equations. So I stick to the theory of partial differential equations, hoping something will turn up some day.

It was after many years before I bumped into the Black-Scholes equation. The Black-Scholes equation was originated in financial economics. From my perspective, this equation is a mapping from lognormal processes. Lognormal processes can be understood as the representation of extracting low entropy to compensate for dissipation, which is the essence of life processes. I sensed that the Black-Scholes theory could lead me further in developing a mathematical theory of living systems.

I started to think about the Black-Scholes theory in 1995,when I was teaching mathematics in Hong Kong. In 1997, I joined an investmentbank. There, I learned to associate mathematical theories with investment decisions. Abstract symbols become concrete.  A year later, I returned to academia , this time as a finance professor in Singapore. After several years, I worked out a theory of economics that provide an analytical relation among major factors in economics: such as fixed cost, variable cost, investment horizon, discount rate and uncertainty. It provides a simple and consistent understanding on broad range of problems in economic and biological systems. More detailed discussion can be found from books and papers written by me and others.

When financial crises or economic downturn occur, they are often blamed on  "unintended consequences" from economic policies. But from our theory, we can solve the equations to obtain quantitative results of long term consequences of those policies. It turns out that the so called unintended consequences are simply long term consequences of the economic policies. Currently, economic policies are mainly measured from their short term impacts. We hope that the introduction of a theory on long term impacts of economic policies will stimulate more active discussion.

Since most prominent economists have a stake in the dominant theory, they are reluctant to discuss rival theories. But mathematicians don't have such concerns. This gives opportunities for mathematicians and other outsiders to make fundamental breakthroughs in economic theories. Neoclassical economics, the current dominant economic theory, was developed around 1870, mainly by Jevons and Walras. Both Jevons and Walras were trained as a scientist and an engineer, not as an economist.

Mathematics has played a substantial role in deepening our understanding of the world. Calculus, stochastic calculus, Maxwell equations Schrodinger equation, Black-Scholes equation are just a few examples. But the applications of mathematics in the vast field of social sciences are still largely cosmetic. By actively engaging in the field of social sciences, mathematicians may crucially impact the future of science and human society.  In the process, we can work on more exciting research that are more relevant to the real world.

References

Systematic discussion about the new economic theory can be found in my two books.

The Physical Foundation of Economics: An AnalyticalThermodynamic TheoryWorld Scientific, Hackensack,NJ (2005)

The Unity of Science and Economics: A New Foundation ofEconomic Theory, (2016), Springer

James Galbraith's book, The End of Normal: The Great Crisis and the Future of Growth, (2015), Simon & Schuster,discussed many of my ideas in great clarity.

More information, including all my papers, can be found from my website

http://web.unbc.ca/~chenj/













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为什么光线弱的地方会觉得浪漫? 2017-08-19 11:21:02

为什么光线弱的地方会觉得浪漫?

情人约会,通常会选光线昏暗的歺厅。恋人散步,通常会选傍晚和晚上。为什么光线弱的地方浪漫一些?

光线弱的地方,眼睛的瞳孔放大,景深变浅,远处的东西看不清,自然,眼睛里面只有她了。

光线强的地方,瞳孔缩小,景深变远,远处的红男绿女看得一清二楚,很难专注。

不知道这个说法有没有道理?



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夕阳 2017-08-17 17:56:50

夕阳

太阳渐渐西斜
光线穿过越来越厚的大气层
当我到达地面
只剩下最能跋涉的红光
那满天的红霞
是我对你最后的眷恋

我也照耀火星
我也照耀金星
可只有地球
孕育了生命

只因生命
才有了青青的草原
才有了红花绿叶
那潺潺的流水
才能多少亿年之后
仍然唱着欢快的歌

火星早已干涸
它衰老的表面满是尘土
只有地球
仍然充满着青春的活力

电闪雷鸣
江河奔腾
麦浪滚滚
雁声阵阵

正午的骄阳
强烈的紫外线
曾灼伤你纤嫩的肌肤
那是我深深的遗憾

年老的我
早已耗尽了尖锐的紫外线
只剩下温柔,温暖的红光
那满天的红霞
是我对你最后的眷恋




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荷花和塘泥 2017-08-13 23:26:28

荷花和塘泥

池塘里的荷花,长得亭亭玉立,风姿摇曳,清香四溢。这些都得益于肥沃的塘泥所提供的丰富营养。但是文人们常常自诩"出污泥而不染",鄙薄哺育了荷花的塘泥,以显示自己的清高。

我们的成长,得益于亲友的养育和帮助,得益于周边的环境。但是对于某些文人,亲情,友情,生我养我的土地,周围的一切都是"眼前的苟且",只有"诗和远方"才值得追求,一下子,境界就比周围的人高出许多。

所有的辛勤劳作,所有的养家糊口,所有的养儿育女,所有的操持家务,都是"眼前的苟且",都是已经出了"污泥"的闲人们所蔑视的,所"不染"的。只有"远方"的风景,才配得上"诗"的吟颂。

有人说,志在远方,有什么不好?这并不是志在远方的问题,而是怎样看待眼前的世界。当年兜售"远方"共产主义信仰的人们,屠杀"眼前"的中国人可是毫不手软。同样,后来推销"远方"的繁荣昌盛,又有多少"眼前"的胎儿被强制打掉。当"眼前"的一切都成了"苟且",无论什么冷酷和冷漠,都在"诗和远方"的包装下,堂而皇之招摇过市。



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