I recently made an informal poll of several colleagues about whether
they preferred to write control coefficients and elasticities in the
logarithmic form, i.e.
dlny/dlnx
or without logarithms, i.e.
(x/y)(dy/dx)
(In both cases please assume that the derivatives are printed or written
in a nicer form than is possible in a plain text message.)
The question was mainly posed in the context of understandability for
readers of papers or students of metabolic control analysis with limited
mathematical expertise, but it may also have wider implications.
The results were more varied (with much more varied reasons given for
the different opinions) than I expected, so it is clear that this is not
a subject with much unanimity at present, and that it may benefit from
wider discussion. I shall not, therefore, try to summarize the views
already received, but will simply pose the same question to the News
Group, and hope that those who have already given a private response
will also give a public one.
My own view, incidentally, was (before asking anyone else) that the two
forms were equivalent and equally easy for students to understand (at
least for those able to cope with the matrix algebra involved in
metabolic control analysis), but that the first was usually preferable
for typographical reasons.
Athel Cornish-Bowden
