In monetary theory the paramount problem posed by many eco- nomists was
always whether monetary variables had a certain influence on the real
variables in the economy, so that money would not be neutral but
influence the economic process. In this way the outcome would differ
from that of a barter economy. The outcome of this development was that
money could no longer be regarded as an accommodating item like in many
out-dated text-books but as an autonomous factor, the influence of which
is explicitly ana- lyzed. When, after the Second World War, the 'real'
side of eco- nomics developed into growth economics, it was quite
natural that efforts were made to integrate both lines of thought so
that the effect of the rate of increase of money on the rate of growth
of real national income could be studied. Dr. Sijben gives the full and
thorough story of these efforts in a way that enables economists to
compare the different approaches more easily than was possible up to
now. More specifically the various models are made comparable by the use
of the same sym- bols for the same variables allover the book. After the
introductory chapter Tobin's outside-money model in a neo-classical
framework is discussed. What is income in this respect? Tobin argues
that real disposable income is real net national income plus the real
value of the increase in monetary balances.