静态与动态

(1)静态与动态

在申述货币的动态学说以前，应该先把静态与动态加以解释。我们读了经典学派(Classical School)的经济学书，常常看见所谓平衡(Equilibrium)字样，就是一种静态的假定。这种假定是说明某种理论的一个步骤，不是事实一定如此。静态是停止的状态(Stationary state，or static state)，是最后的结果。自然界的现象，如水、电、温度等，每每从不平的状态趋向于平衡。经济的现象也是如此。关于此点，耐特(F.H.Knight)说得最为明了:

“The reference to final results calls for a further word.The concept of equilibriumis closely related to that of static method.It is the nature of eve ry change in the universe known to science to have‘final’results under any given conditions，and the description of the change is complete if it stops shortof the statement of these ultimate tendencies.Every movement in the world is and can be clearly seen to be a progress toward an equilibrium.Water seeks its level，air moves towards an equality of pressure，electricity toward a uniformpotential，radiation toward a uniformtemporature，etc.Every change is an equalization of the forces which produce thatchange，and tends to bring about a condition in which the change will no longer take place.The water continues to flow，the wind to blow，etc.，only because the sun's heat—itself a similar butmore long-drawn-out redistribution of energy—constantly restores the inequalities which these movements themselves constantly destroy.”

“So also in economic phenomena.Goodsmore fromthe point of lower to one of the higher demand or price，and every such movement abliterates the price difference which causes it.The circulation of goods continues because the life activities of man(the production of wealth)keep new supplies forthcoming.The same applies to shifts in productive energy fromone use to another...It is arbitrary but convenient to speak of the static state in relation to given conditions of the supply and demand(production and consumption)of consumption goods.”^[30]

耐特并引克拉克(J.B.Clark)，将经济理论分为3种状态:①自然现象，②静态的社会现象，③进步的社会现象。经济学派所谓静态，即所谓“天然”状况，必须排除5种变化而后可以实现。

“The dynamic theory is a correlate of Professor J.B.Clark's theory of distribution in the profitless‘Static State’.Professor Clark outlines a systematic structure of theoretical economics in three main divisions.

The first treats of universal phenomena，and the second of static social phenomena.Starting with those laws of economics which act whether humanity is organized or not，we next study the forces that depend on organization but do not depend on progress.Finally it is necessary to study the forces of progress.To influences that act if society were in a stationary state，we must add those which act only as society is thrown into a condition ofmovementand disturbance.This will give us a science ofSocial Economic Dynamics.”—Distribution ofWealth，pp.30-31.

“The static state is the state of‘natural’adjustments of Ricardo andearly classical writers.

‘What are called“natural”standards of values or“natural”or normal rates ofwages，interest，and profits are in reality，static rates.They are identical with those which would be realized if a society were perfectly organized，but were free from the disturbances that progress causes...Reduce society to a stationary state，let industry go on with entire freedom，make labour and capital absolutely mobile...and you will have a régime of natural values．’”—Distribution ofWealth，p.29.

“To realize the static state，we should have to eliminate five kinds of change which are constantly in progress:

Five generic changes are going on，every one of which reacts on the structure of society，by changing the arrangements of that group system which it is the work of catallactics to study:

1.Population is increasing.

2.Capital is increasing.

3.Methods of production are improving.

4.The forms of industrial establishments are changing，the less efficient shops，etc.，are passing from the field，and the more efficient are surviving.

5.The wants of consumers are multiplying.”—Distribution ofWealth，p.56.^[31]

向蒲彼得(J.A.Schampeter)解释静态与动态，意见稍有不同。他说，经济变动的原因有二:一是经济制度以外的变动，一是制度本身的变动。后者尤为重要。制度发生变动，即可产生新的平衡。旧的制度无论如何延长决难达到此新平衡。

“In the first edition of this book，I called it‘dynamics’.But it is preferable to avoid this expression here，since it so easily leads us astray because of the associations which attach themselves to its variousmeanings.Better，then，to say simply what we mean:economic life change;it changes partly because of changes in the data，to which it tends to adapt itself.But this is not the only kind of economic change;there is another which is not accounted for by influence on the data fromwithout，but which arises fromwithin the system，and this kind of change is the cause of so many important economic phenomena that it seems worth while to build a theory for it，and in order to do so，to isolate it from the other factors of change.The author begs to add another exact definition which he is in the habit of using:what we are about to consider is that kind of change arising fromwithin the systemwhich displaces its equilibriumpoint that the newone cannot be reached fromthe old by infinitesimal steps.Add successively asmany coaches as you please，you will never get a railway theory.”^[32]

向蒲彼得说，静态不是停止状况(Stationary state)，与克拉克的意见不同。他说，理论与事实不是一样。在历史的演进中，经济衰落虽然是停止状况，但理论上所假定的静态不是如此。两者常相混淆。

“Static theory does not assume a stationary economy;it also treats of the effects of changes in data.In itself，therefore，there is no connection between static theory and stationary reality.Only in so far as one can exhibit the fundamental formof the economic course of events with the maximum simplicity in an unchanging economy does this assumption recommend itself to theory.The stationary economy is uncounted for thousands of years，and also in historical times in many places for countries，an incontrovertible fact，apart fromthe fact，moreover，which Lombart emphasised，that there is a tendency towards a stationary state in every period of depression.Hence，it is readily understood how this historical fact and that theoritical construction have allied themselves in a way which led to some confusion.”^[33]