1. The determination of total labor income (LI) must be understood on a country-by-country basis.
This geopolitical limit is a consequence of the nature of the variables of this determination. Everything that makes a population more or less skilfully industrious affects what the total per capita income is for it, this income per capita being always liable to be more or less different from one country to another.
2. With "=" meaning "is determined by", we have shown that LI = TI – RP.
It should be remembered that it is the long-term problem of the distribution of total income that is considered here.
3. By definition of investment return (ROI), total saving placement income (SI) is equal to multiplying ROI by the amount of investment stock (SDP).
RP = RDP x SDP
As per the definition of Productivity of savings in capital (PPP):
SDP = TI / PDP SI = RDP x (RG / PDP)
4. Since LI = TI – RP:
RT = TI – [RDP x(RG/PDP)]
Total labor income (TA) is determined by a difference whose variables are total income (TI), return on investment (ROI) and Productivity of savings in capital (OF).
5. From the equation LI = TI – [RDP x (RG / PDP)] all cases of progression, stagnation and regression of the LI can be deduced.
In particular, there is an increase in total labor income, RT, when there is simultaneously:
1) increase in GR, 2) stability in ROP, 3) increase in PDP.