QFDs of various countries. Four studies identified private sector involvement as leading to a significant reduction in losses, and one study found a significant positive relation to bill collection.

One surprising finding is that unbundling on its own was found to be significant in only one case (plant load factor), but only five out of 22 tests included this variable. Four tests included the interaction between unbundling and competition (three were significant) but none of these tests included private sector involvement in any form. This also points to a lack of coherence in the treatment of facilitating variables in these regression models. Several tests included regulation as a policy variable, although it is not normally concerned with the interior working of the firm. Out of 12 tests only three showed a significant effect of regulation on these performance indicators.

A second group of tests (type II) looked at performance indicators that directly link the firm to its customers, and, if policies were identified as successful, consumers would have benefited from their adoption.

_Access as measured by the number of connections per household or in total_ was subjected to some of the most sophisticated modeling. Only one of the five studies tested for the effect of unbundling on its own, but all tested for the effect of private sector involvement. In four cases private sector involvement was significantly linked to an increase in access, and three studies also indicated that regulation contributed significantly to access. Two studies checked for the effects of competition and one of these was also significant, as were transition variables. Rather than using simple dummy variables, three of the studies also used measures of degree for private sector involvement, for the independence of regulation, and for competition. Overall, these results pointed to sector reform being successful in increasing access, particularly when a strong regulator existed and there was a substantial private sector involvement with ample competition.

_The quality of service as measured by the frequency and the duration of interruptions_ is expected to improve after the entry of the private sector and these affects were found to be significant in the one study which included these variables. No other policy factors or the degree of private sector involvement were included.

Some studies also linked reform policies to prices charged, but the role of subsidies was not evaluated at the same time. A reforming government might well have decided to also reduce subsidies, hoping that efficiency gains from reform would help offset the subsidy reduction effect on prices. Without an analysis of the subsidy policy, correlating tariffs with policy variables cannot be relied on to give an unbiased estimate of these policy interventions. For this reason, tests of the relation between prices and policy variables are not reported.

The tests on performance variables that directly impact users of electricity provided some strong evidence that reforms produced significant improvements in performance. Access responded positively to private sector involvement, regulation, and competition; generation capacity 39