Tuesday, 27 October 2009

Economic notes -- three basic economic problems

The three economic basic problems 1) What to produce? (Types and quantities of goods/services to produce) 2) How to produce? (Production methods) 3) For whom to produce? (How to distribute goods and services) Solutions to the three economic problems 1) By customs and traditions (Tradition economy) , e.g., decided by the father or eldest son in a family. 2) In a planned economy, resources are allocated by government plans and commands and people have to follow that in production and consumption. 3) In a market economy, most resources are owned privately. Resources are allocated by market mechanism or price system as a signals to guide resource allocation. Market economy: -Minimize government intervention -Resourced owned by private individuals -Economic decisions made by market prices -Resources allocation and distribution of goods by market prices Planned economy: -Government intervention is common -Resources owned by the state -Economic decisions made by the government -Resources allocation and distribution of goods by government command

Specialisation and exchange 1) Specialisation is a way of organizing production, different people/economics concentrate on producing different goods. Workers concentrate the job they’re best at. Then production cost can be reduced. 2) Exchange (trade) is an important condition for specialisation. Without exchange, then everyone have to produce all good by itself and specialisation can’t happen. 3) Private property rights – A good is a private property of someone if the owner has the following right: - exclusive right to use - exclusive right to receive income generated by the use of the good - right to transfer (not exclusive in all cases) If it’s not exist or not clearly defined, then goods become common property, then exchange can’t be happen so as specialisation. Then, it encourages non-price competition such as violence. If it’s clearly defined, then buyers can obtain good if the buyers can pay a certain price. Resources can be allocated to those who place the highest value on them. Positive statements talk about facts, no value judgments, some of them are refutable. Normative statements is about what should be, its about value judgment. Economic is a social science and we use scientific methods to develop theory. i.e., economics is positive.

Economics Note -- What is economics?

(Hi there. In this year I can only type notes on economics, Physics, Chemistry, probably some maths technique and LS passage.) (graph skipped.)

Opportunity cost: Highest-valued option forgone (cost of the best alternative use) Rules: 1) We only count the highest-valued option forgone, i.e., only one option is counted as cost. 2) No other (possible) choice implies no cost. 3) Cost change if and only if value of highest-valued option forgone changed, i.e., change of value on other alternatives or the chosen options will not change the cost. 4) Full cost = money cost (money spent) + non-money cost (resources spent other than money). Time cost can be monetary (in terms of income forgone) or non-monetary (in terms of another activity forgone). 5) Option considerable for cost is the option available at the moment. Paid in the past will not be counted,

Bad: We don’t desire / prefer less to more Good: We desire / prefer some to none Economic (or scarce) good: Available quantity can’t satisfy all human wants for it. Human are willing to pay for it. More of them is preferable. Free Good: Available quantity can satisfy all human wants. No one is willing to pay for it. More of them is not preferable, we only get the amount we need.

Note that free good must be free of charge, but good that is free may not be free good. Production is the process that transforms resources to goods and services. Factor of production: 1) Labour is a type of human resources. They earn wages and work for production. 2) Entrepreneurship (entrepreneur) is to organize production, making decisions and bearing risk. They earn profits for risk-taking. 3) Capital is a type of man-made resources. It is used to help production. Capital owners earn interests by providing capital. 4) Land is a type of natural resources. Land owners earn rents by providing natural resources for production. Consumption – activity to satisfy human wants. Both present and future consumption are economic goods (prefer more), since we are impatient (earlier time preferences), present consumption has a higher value than future consumption. Therefore people are willing to pay more for earlier consumption. They may borrow money and repay the money plus the interest. Therefore for a borrower, interest is the cost of earlier availability of goods or resources. They pay extra interest for earlier consumption. For a lender, interest is the compensation for deferring consumption of goods (or use of resources). They scarified money in the present and get more in the future. Then, interest rate shows the cost of earlier consumption. Flow of economic activities Firms – unit of production Household – unit of consumption Real flow (flow of goods and services including factor services): Household providing factor services to factor market and to the firms, then the firms provide goods and services to the household through product market. Money flow (money income and expenditure): For household, they provide factors services and get factor income. They pay for good and services from firms. For firms, they pay for factor services, and earn revenue from providing goods and services to household. Their exchange on good, service, income and expenditure through the factor market and product market, also household and firms are inter-related. Macroeconomics and microeconomics Microeconomics is the study on behavior of individual economic units. Macroeconomics is the study of the performance of an economy as a whole.

Friday, 16 October 2009

一萬字 Ch.13

「也不是那麼可怕啦~只不過打風踩單車比較危險,加上以前真的死過人,所以才會有這個名字嘛。」 「那,比賽會何時開始?」 「按例是一號風球掛起後的第二個晚上。」 「……為甚麼要第二晚?那不是更大風嗎?」 「大風才更好玩嘛。」 「……」 對話結束便時一課比較趕的集訓。跟昨天的訓練不同,集訓要練習的技巧更多。到現在為止,我也許還沒見過紫欣的真正實力。原因是,她今天做出了一堆花式出來,除了目瞪口呆的我外,其他的隊員只是顯出一副稀鬆平常的樣子,彷彿那些花式每天都會見十遍八遍那樣……看來我還沒接受到面前的少女是單車天才這個事實。 「喂!」 一聲清脆的叫聲響起,打亂了我的思緒。 「如果你不好好看著和練習的話,明晚的比試就真的會變成死亡遊戲了哦!」 「啥?」 「因為,在打風的環境下沒有花式的人就是在玩命。」我這才意識到紫欣正在叉著腰,生氣地瞪著我。 「對,對不起……」我垂下了頭。 「……我還是再示範一次好了。」 她騎上單車,做出了個幾乎完美的花式。在一段加速後,她把前輪停在半空,但同時後輪仍能推動單車前進,她自轉一圈後衝往牆壁──前輪沿牆壁滾動──優美的完成了一個凌空翻騰。 「你覺得這招厲害嗎?」 「還好啦,不過這只些在打風時有用嗎?」 她笑了笑道:「你試試就知道了吧~反正當你要隨機應變時都有機會要用啦。」 …… 就這樣,所謂的集訓就打打鬧鬧地結束了。 雖然我說不出這裡正確的地理位置,不過大約是大埔吧。大埔雖然不屬離島,但往往有「市區春江鴨」的作用。也就是說,大埔變得當風意味著市區的風勢會逐漸增加,所以大埔會不會吹持續的強風也反映了發出「三號波」的可能性。 走出體育館,外面仍是一片平靜,完全沒有要打風的感覺;陽光普照、萬里晴空彷彿在嘲笑著這個無理的一號風球。 這對我反而是一個警示。 真的是萬里晴空嗎? 當熱帶氣旋離香港一段距離時,香港就會受到其下沉氣流影響變得悶熱;但當熱帶氣旋更接近香港時,天氣便會迅速轉壞,狂風也變得明顯。 「一號風球掛起後的第二個晚上。」她是這樣說的。 也就是說,一號發出後的約四十小時。 四十小時,熱帶氣旋能走多遠呢?慢的話,可能兩天後還是一號;快的話如果熱帶氣旋時連十六、七公里,那,四十小時後就幾乎是最接近的時間了。 級數不弱的熱帶氣旋只要在香港以南掠過,便可以發出八號…… 情況不太樂觀呢。

Saturday, 10 October 2009

10-10-09

雙十節~ 終於完成了2份大型notes -Basic algebraic Skills Algebraic skills : moving terms, sub. skillsm factorization Function : Polynomial, f_n(x) Sequence : AP, GP, recursive Solving equation : quadratic, simultaneous equation Complex number : De morive's theorem, Arg, absolute value Absolute value function Logarithm function Root function integer and decimal function Inequality -Basic Number Theory Skills Divisibility Congruence Diophantine equation