摘要：Strategic trade in international markets is important for agricultural and other basic commodities. Distribution systems for these commodities are dominated by agents that have the potential for exclusive monopoly power. State trading companies (STC) and large private firms control most of the trade volume. For agriculture in particular, the seasonal nature of the production process compared to a relatively constant demand for the commodities brings into play as well concepts of timing in trade contracting and time consistent behavior. Some of the earliest papers that investigate issues of time consistency in trade are Lapan (1988), Maskin and Newbery (1990) and Staiger and Tabellini (1987). Melkonian and Johnson (1996) have explored a model in which an STC, which has monopsony power, cannot credibly commit to a particular policy or contract. An annual trading cycle was considered. In the sequence of economic decisions, the STC moves first and announces a planned level of import. Producers in the exporting countries make their decisions on the allocation of the more fixed inputs (e.g., land) based on related price expectations. However, before they make decisions on the allocation of the more variable inputs (e.g., labor or fertilizer), the STC has the opportunity to revise the announced level of imports. Then, the labor or variable input allocation decisions of the producers are made, given the revised (and predetermined) level of imports and the previous allocation of the more fixed inputs. Finally, trade takes place.
