three other countries. In effect, this country is the only one that shows salient and special flows with all the other countries of the region. It should be noted that the salient flow between Honduras and Guatemala was lost in 1981, although the special flow between Honduras and Costa Rica was maintained. In effect, it appears that Honduras has a "propensity" or "preference" to establish "special" ties with Costa Rica, while its links to Guatemala are unstable. 8 + ̰/
It should be underlined, nevertheless, that although there exists a considerable distance between Costa Rica and Guatemala, the important flow between these countries was maintained, which could be explained by their high levels of industrial production. In this way the volume of industrial production could be conceptualized as an impulsive element that attenuated spatial friction. 9 + ̰/
It is through the analysis of salient, special, and important flows that the distinct characteristics of trade within the Central American Common Market (CACM) can be perceived. The wide corridor of salient flows from the north to the south in 1977 and 1978 suggests the existence of solid economic interdependence (see Figures 6.5 and 6.6). Clearly, Costa Rica was solidly integrated with Guatemala and El Salvador, not only through direct linkages, but also indirectly, through its external connections with Nicaragua and thence to Honduras, and then from Honduras to Guatemala. This is to say, Costa Rica, on one side, and Guatemala and El Salvador on the other, benefited from the bridge effect that Honduras and Nicaragua offered to their reciprocal economic stimuli.
In the last years of the analysis there is an appreciable loss of salient flows, and the corridor appears to be obstructed. This has the potential of creating two poles of integration in the region. Because of the absence of a "super-corridor," the countries of the north would not receive fully the incoming stimuli arising from the south (especially Costa Rica), and vice-versa: Costa Rica would not receive growth impulses from the economies of Guatemala and El Salvador. This indicates the necessity of fortifying the Central American integration system, and intrazonal trade in particular, within a global context. Therefore, a regional focus is required to address the area's problems.