宋圭武觀點181消費函數需要新定義

消費問題是經濟最重要的問題之一，消費函數自然也是需要重點研究的經濟學内容之一。凱恩斯最早提出消費函數這一概念，他認為，總消費是總收入的函數。庫茲涅茨認為，長期消費是收入的一個固定比率，在長期内，平均消費傾向大體穩定。斯密塞斯認為，在短期内，消費是現期收入的函數，并且消費水準随現期收入水準提高而比例減少，而儲蓄則随現期收入水準增加而增加；在長期内，消費除受收入影響外，還受其它諸多因素影響。杜森貝裡認為，人們的消費存在互相攀比現象，同時，消費還具有一定的慣性。弗裡德曼認為，人們的消費主要取決于持久收入。莫迪利安尼通過生命周期說解釋消費問題，認為消費者是根據生命周期來安排個人最佳消費。還有一些學者在消費函數中加入理性預期因素，理性預期也成為影響消費的一個重要變量。等等。

總之，現有各種消費函數普遍存在兩個方面的問題和不足：一是隻考慮一個人現世的消費效用滿足，沒有考慮到或較少考慮到一個人對來世消費效用的安排；二是更多考慮物質層面的消費效用，缺少精神層面的消費效用考慮。個人認為，一個人的消費函數，在消費效用滿足方面，不僅要考慮現世的效用滿足，還要考慮來世的效用滿足問題，尤其在一些宗教文化濃厚的社會，人們的一些消費，與滿足來世效用是高度相關的，甚至更重視來世效用的滿足。另外，人們的消費不僅僅是隻考慮物質效用的滿足，還同時考慮精神效用的滿足。在消費成本支出考慮方面，不僅考慮物質成本支出，也考慮精神成本支出，不僅考慮現世的物質成本和精神成本支出，也考慮來世的物質成本和精神成本支出，最終消費成本考慮是這四個方面成本的總和。

與物質收益存在邊際遞減規律一樣，在精神收益方面，也存在邊際收益遞減規律。比如，一個人榮譽過多，必然增加同一級别榮譽所帶來的邊際精神收益會遞減，除非後面的榮譽等級要比前面的榮譽等級更高，才可能邊際收益遞增。

在邊際收益遞減規律作用下，一個人的物質收益和精神收益，二者也存在一定程度邊際替代特征。比如在物質貧困狀态下，可能一個人會更多通過損失精神收益換取物質收益，一個人在物質富裕情況下，可能會更加注重追求精神收益，慈善也可能會多一些。人們常說，倉廪實而知禮節，衣食足而知榮辱，反映的就是這種情況。還有，一個人随着收入的增加，可能會更加注重消費的相對效用，比如可能會産生一些炫耀性消費等，這也與增加精神收益有關。當然，上述情況也存在諸多例外，結論不能絕對化。

在特定的環境下，消費還存在消費異化問題，即消費過程否定消費者自身存在的真正價值。産生消費異化的原因是多方面的。人性的貪婪自私、不合理的分工結構、制度的不公正、文化的不合理等，都可能導緻消費異化問題。好，謝謝，謝謝。

Song Guiwu's view 181 Consumption function needs new definition

Consumption is one of the most important issues in economy, and consumption function is naturally one of the economics contents that need to be studied. Keynes first put forward the concept of consumption function. He believed that total consumption is a function of total income. Kuznets believed that long-term consumption is a fixed ratio of income, and in the long run, the average consumption tendency is generally stable. Smithers believed that in the short term, consumption is a function of current income, and the consumption level decreases with the increase of current income level, while the savings increase with the increase of current income level; in the long run, consumption is affected by many other factors besides income. Duesberg believed that people's consumption exists the phenomenon of keeping up with each other, and at the same time, consumption has a certain inertia. Friedman believed that people's consumption mainly depends on their permanent income. Modigliani explained the consumption problem through the life cycle theory, and believed that consumers arrange their best consumption according to the life cycle. There are also some scholars who add rational expectation factors into the consumption function, and rational expectation has also become an important variable affecting consumption. And so on. In a word, there are two problems and deficiencies in the existing various consumption functions: one is that only one person's present consumption utility is satisfied, without considering or less considering one's arrangement for the afterlife consumption utility; the other is that more consideration is given to the consumption utility on the material level, while less consideration is given to the consumption utility on the spiritual level. Personally, one's consumption function, in terms of consumption utility satisfaction, should not only consider the satisfaction of the present utility, but also the satisfaction of the afterlife utility. Especially in some religious culture society, some of people's consumption is highly related to the satisfaction of the afterlife utility, and even attaches more importance to the satisfaction of the afterlife utility. In addition, people's consumption is not only considered the satisfaction of material utility, but also the satisfaction of spiritual utility. In terms of consumption costs, not only consider the material costs, but also consider the spiritual costs, not only consider the material costs and spiritual costs of the present, but also consider the material costs and spiritual costs of the afterlife. The final consumption cost is the sum of the four aspects of cost. As there is a law of diminishing marginal returns in material income, there is also a law of diminishing marginal returns in spiritual income. For example, a person with too much honor, the marginal spiritual income brought by the increase of the same level of honor will decrease, unless the latter honor level is higher than the former honor level, the marginal returns may increase. Under the law of diminishing marginal returns, a person's material income and spiritual income, both also have a certain degree of marginal substitution characteristics. For example, in the state of material poverty, a person may lose more spiritual income in exchange for material income, a person in the case of material affluence, may pay more attention to the pursuit of spiritual income, charity may be more. People often say, "the grain is full and the etiquette is known, and the clothes and food are enough to know honor and disgrace", reflecting this situation. In addition, with the increase of income, a person may pay more attention to the relative utility of consumption, such as conspicuous consumption, which is also related to the increase of spiritual income. Of course, there are many exceptions to the above situation, and the conclusion can not be absolute. In a specific environment, there is also the problem of consumption alienation, that is, the consumption process denies the true value of the consumer's own existence. The reasons for consumption alienation are many. Human greed and selfishness, unreasonable division of labor structure, institutional injustice, and irrational culture may lead to consumption alienation. OK, thank you, thank you.