en stated and argued in quantitative form. As
Professor Marshall said the other day, _qualitative_ reasoning in
economics is passing away and _quantitative_ reasoning is beginning to
take its place.[43]

[43] _Journal of Economics_, March 1907, pp. 7 and 8. 'What by chemical
analogy may be called qualitative analysis has done the greater part of
its work.... Much less progress has indeed been made towards the
quantitative determination of the relative strength of different
economic forces. That higher and more difficult task must wait upon the
slow growth of thorough realistic statistics.'

How far is a similar change of method possible in the discussion not of
industrial and financial processes but of the structure and working of
political institutions?

It is of course easy to pick out political questions which can obviously
be treated by quantitative methods. One may take, for instance, the
problem of the best size for a debating hall, to be used, say, by the
Federal Deliberative Assembly of the British Empire--assuming that the
shape is already settled. The main elements of the problem are that the
hall should be large enough to accommodate with dignity a number of
members sufficient both for the representation of interests and the
carrying out of committee work, and not too large for each member to
listen without strain to a debate. The resultant size will represent a
compromise among these elements, accommodating a number smaller than
would be desirable if the need of representation and dignity alone were
to be considered, and larger than it would be if the convenience of
debate alone were considered.

A body of economists could agree to plot out or imagine a succession of
'curves' representing the advantage to be obtained from each additional
unit of size in dignity, adequacy of representation, supply of members
for committee work, healthiness, etc., and the disadvantage of each
additional unit of size as affecting convenience of debate, etc. The
curves of dignity and adequacy might be the result of direct estimation.
The curve of marginal convenience in audibility would be founded upon
actual 'polygons of variation' recording measurements of the distance at
which a sufficient number of individuals of the classes and ages
expected could hear and make themselves heard in a room of that shape.
The economists might further, after discussion, agree on the relative
importance of each element to the final decision,