It is shown that the profitability i is given by (8) and (9).
From (1) we have

From (7) and (B1) follows that

Comparing the right-hand side of (B2) and the left-hand side of (A2) it is easy to see, after replacing x by g in (A2), that analogously with (A9) it follows from (B2) that

After some algebra (B3) can be written as

Denoting

(B4) becomes

Solving i from (B5) gives (8).
The next section (Appendix C)
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previous section (Appendix A)
The contents section of Ruuhela, Salmi, Luoma and Laakkonen (1982)
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