Answer:
PPF : Downward Sloping Straight Line
Step-by-step explanation:
PPF is the locus of product combinations that an economy can produce, given resources & technology.
It is downward sloping : Because of inverse relationship between two goods- if one has to be increased other has to be decreased , because of same resources & technology.
Marginal Opportunity Cost (Slope of PPC): is ratio of a good sacrifised to gain each additional unit of the other good.
∆ Good sacrifised / ∆ Good gained
If this ratio is same i.e constant amount of a good is sacrifised to gain an additional amount of the other one , the slope of PPC is constant & it is a straight line
Eg : Good1 Good2 MOC [∆Good2/∆Good1]
0 20 _
10 10 -10/10 = -1 (10-20)/(10-0)
20 0 -10/10 = -1 (0-10)(/20-10)
So , same (1) good 2 is sacrifised to attain a good 1 each time.
However Generally: MOC is increasing , because of assumption that resources are unequally efficient in various goods production - shifting good from efficient to inefficient increases sacrifise each time. This makes PPC usually concave.