贳 , , ., .. . "" (1988).[31][31] , ̳ , " ",[32][32] . - , - - , , .[33][33] , . ͳ, 30- 1988 (. 1).
)
)
1.
: Paul A.Samuelson, William D.Nordhaus and John McCallum. Economics.- Toronto etc.: McGraw-Hill Ryerson, 1988.- P.786.
-- :
= f (, ), (1.6)
- ;
- ;
- .
ϳ
ϳ , , . , . . , " .... , ...".[34][34] :
) ;
) , ;
) .