tions are defined in advance; that linkages between member organizations are well understood; and that adequate resources are available to support interorganizational linkages. Networks function better if there is consensus on the tasks expected of each member; if each member has adequate resources to do the expected work; if the cost to each member for membership is low; and if the leaders of member organizations need not fear loss of organizational autonomy as a result of participating in the network. Effective networks tend to include boundary personnel (people who have the job of interacting with other organizations), individuals who belong to several organizations in the network, interorganizational boards and committees, and a superorganizational board. Ideally, interorganizational interactions are frequent and reciprocal rather than one-way, and communication patterns are clear, open, and broad as to content. In addition, networks are more likely to be effective if they are composed of smaller numbers of organizations that are compatible in terms of goals, function, and scope and if they have been initiated by their member organizations rather than created by outside request or legislative mandate (Mileti and Sorenson, 1987).
Market institutions have not been much studied as coping mechanisms for climatic variability, but this is one of the functions they serve. Two examples illustrate. One is the emergence of global markets for grains and other foods. These markets reduce the dependence of human populations on food grown nearby and therefore their dependence on local climatic conditions. They also allow producers to benefit from climatically induced food shortages elsewhere by supplying food to those areas. These effects, however, are contingent on the ability of producers and consumers to participate in the global markets. For consumers, this means having money to purchase food at market prices and access to distribution networks; for producers, it means the ability to ship their products. Thus, markets alone do not insulate the poor from the effects of climatic variation nor secure benefits for producers in remote areas. Nevertheless, to the extent that global food markets function well, they spread the risks and benefits of climatic variability worldwide.
A second example of how markets help cope with climatic variation is the functioning of commodities futures markets. These markets allow producers and distributors of food and other weather-sensitive commodities to hedge against climatically induced variations in production by guaranteeing themselves the price or availability of a known quantity of the commodity at a later date. As with food markets, futures markets do not benefit everyone equally. To benefit from the potential to hedge, an