As a matter of course, how important a subject it is for the fosest policy in Japan to make supply and demand balance of timber, is of vital interest and concern. Futhermore, with the boundary of timber utilization extending, the need for timber is increasing, and will do moreso as time goes on.
It means, of course, that itself easily and unjustly influences a rise or a decline in price when there is an under-supply or an over-supply, which in turn adds to the violence of the change in times of prosperity or depression.
Therefore, in order to prevent the unbalance caused by fluctuations in supply and demand of timber in Japan, we must endeavor to find an index or some indications that will lead to effective and concrete (or practical) measures that can be applied to stabilize the national economy pertaining to timber. That is to say, this is the measuring to seek a concrete supply and demand law, and the aim of this work is to establish such a law or theory.
We shall take into consideration the market's determining factors that influence the supply and demand of timber, among them, income, experimental timber's and demand, and others besides the price of timber as it is cleared by the following description.
Now, in order to arrive at and fix upon the supply and demand theories of timber in Japan, we will try to establish a model of timber's supply and demand functions, basing our considerations on the most important factors of the market's determining factors.
Thus we get:
1) d=f(p) d; Time-independent per head (average) timber demand
2) d_t=λ(P_t, y_t) p; Time-independent real timber price factor
t; Factor of the time trend
3) d_t=φ(P_t, y_t, t) d_t & d_t-1; Per head (average) timber demand at t & t-1 period
4) d_t=_??_(P_t, y_t, y_t-1) P_t; Real timber price factor at t period
5) d_t=θ(y_t, y_t-1, d_t-1) y_t & y_t-1; Real income factor at t & t-1 period
6) {D_t=D(P_t, P_t) Dt; Total timber demand at t period
S_t=S(P_t-1, σ_t) P_t & P_t-1; Timber price factor at t & t-1 period
D_t=S_t ρ_t & σ_t; Random factor on demand side & supply side at t period
In that way, we will certificate with the statistical figures on the market, how the actual supply and demand theories of timber are carried through into the aboveestablished models of supply and demand functions of timber.