Abstract
The purpose of this paper is to show an empirical test of subadditivity based on a sufficient condition - namely, transray convexity coupled with global economies of scale - which has not been commonly used in the literature. We use this sufficient condition to test the hypothesis of subadditivity of the cost function in the largest Portuguese Telecommunications firm, CTT, and find that the market for telecommunications services in Portugal was a natural monopoly in the period analysed.
| Original language | English |
|---|---|
| Pages (from-to) | 489-494 |
| Number of pages | 6 |
| Journal | Applied Economics |
| Volume | 25 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 1 Apr 1993 |