Fabrizio
ERBETTA
University of Eastern Piedmont, HERMES
Luca RAPPUOLI
University of Eastern Piedmont, HERMES
The Italian gas distribution industry presents a
high degree of fragmentation. However, the tendency of the market
during the period comprised between 1970 and 1998 points out a concentration
process. The available evidence supports the thesis that the local
distributors have undertaken a process of enlargement of their scale
size. This raises the question about the characteristics of returns
to scale for such operators as well as the optimal scale at which
they should operate. Returns to scale are analysed by means of DEA
(Data Envelopment Analysis) methodology. The finding points out that
the output space along which DMUs attain a high level of scale efficiency
is very spread, so indicating an unexpected returns to scale characterisation.
Only for smallest units the technology shows increasing returns, but
such effect get rapidly exhausted in favour of a regime of constant
returns to scale. The main policy conclusion is that an improvement
of productivity can be reached by an intensification of the merging
process involving local distributors operating at small scale. In
addition, the mentioned concentration process appears as an "attainable"
objective since the critical dimension allowing the exploitation of
positive returns to scale is quite small.