预习任务
通过预习，尝试思考下列问题:
1. 举例说明并解释两个以上的注入因素。
2. 举例说明并解释两个以上的漏出因素。
3. 消费和投资的增加()
A. 国民收入减少
B. 国民经济总财富量减少
C. 国民经济总产出水平增加
D. 国民经济总产出水平不变
Leakage(withdrawal) and injections
In the five sector model the economy there is leakage and injections
Leakage means withdrawal from the flow. When households and firms save part of their incomes it constitutes leakage. They may be in form of savings, tax payments, and imports. Leakages reduce the flow of income.
injections means introduction of income into the flow.When households and firms borrow the savings,they constitute injections.Injections increase the flow of income.Injections can take the forms of (a) investment,(b) government spending and (c) exports.So long as leakages are equal to injections circular flow of income continues indefinitely.Financial institutions or capital market play the role of intermediaries. This means that income individuals receive from businesses and the goods and services that are sold to them do not count as injections or leakages, as no new money is being introduced to the flow and no money is being taken out of the flow.
Leakage and injections can occur in the financial sector, government sector and overseas sector:
In terms of the circular flow of income model the leakage that financial institutions provide in the economy is the option for households to save their money. This is a leakage because the saved money can not be spent in the economy and thus is an idle asset that means not all output will be purchased. The injection that the financial sector provides into the economy is investment (I) into the business/firms sector. An example of a group in the finance sector includes banks such as Westpac or financial institutions such as Suncorp.
The leakage that the Government sector provides is through the collection of revenue through Taxes (T) that is provided by households and firms to the government. For this reason they are a leakage because it is a leakage out of the current income thus reducing the expenditure on current goods and services. The injection provided by the government sector is Government spending (G) that provides collective services and welfare payments to the community. An example of a tax collected by the government as a leakage is income tax and an injection into the economy can be when the government redistributes this income in the form of welfare payments, that is a form of government spending back into the economy.
The main leakage from this sector are imports (M), which represent spending by residents into the rest of the world. The main injection provided by this sector is the exports of goods and services which generate income for the exporters from overseas residents. An example of the use of the overseas sector is Australia exporting wool to China, China pays the exporter of the wool (the farmer) therefore more money enters the economy thus making it an injection. Another example is China processing the wool into items such as coats and Australia importing the product by paying the Chinese exporter; since the money paying for the coat leaves the economy it is a leakage.
Summary of leakage and injections
LEAKAGES | INJECTION |
| Saving (S) | Investment (I) |
| Taxes (T) | Government Spending (G) |
| Imports (M) | Exports (X) |
