Figure 2

The event data record of USA-USSR interactions correspond closely to the patterns one would expect from an historical study. Moreover, the event data can also be used to fine-tune that chronology. For example, while Nixon clearly intended to implement a détente policy from the beginning of his administration in 1969, there was continued disagreement between the USA and USSR over the US involvement in Vietnam, the 1968 Soviet invasion of Czechoslovakia and other issues, so the interaction pattern is not actually positive until 1971. Positive interactions peak about the time of Nixon's resignation in 1974; the event data scores then decline during the two years of the Ford administration and return to post-Cuban Missile Crisis levels by 1976.

Figure 2 shows another example of the use of event data to chart the evolution of a complex international interaction, the Palestinian intifada (uprising) that began in December 1987. This chart is based on the coding of news stories on Israeli-Palestinian reported by the Reuters international news agency. These reports were coded by KEDS into the WEIS event data categories, then converted to a monthly numerical score using a scale devised by Goldstein (1992). As in Figure 1, negative scores indicate conflict and positive scores cooperation.

This time series shows the pattern of interactions--largely uses of force--in considerable detail. The initial increase in conflictual activity in 1982-83 corresponds to Israel's invasion of Lebanon, which was initially directed against Palestine Liberation Organization forces. The invasion is followed by a period of five years of relative quiet, though a separate series of event data on Israel's interactions with Lebanon during this period shows a great deal of conflict as opposition to Israeli forces shifts from the PLO to various Lebanese groups. The intifada begins abruptly in December 1987 and then gradually declines over the next five years, though there is another upsurge in violence following the election of a Labor government in Israel in the summer of 1992.

As with the case of the USA-USSR interactions, this time series gives a more exact measure of the patterns of events over time. For example, while the intifada follows a lull in conflict during the summer of 1987, the event data also show a general increase in conflict beginning about 18 months earlier. This increase may have been a precursor to the larger uprising.

Figure 2: Israel-Palestinian interactions, 1982-1992

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(You can experiment further with this data set using the KEDS_Display computer program)

As these two figures illustrate, event data can be used to summarize the overall relationship between two countries over time. The patterns shown by event data usually correspond to the narrative summaries of the interactions found in historical sources, but unlike narrative accounts, event data can be subjected to statistical analysis. As a consequence, event data are frequently used to study foreign policy outcomes and some characteristics of the international environment within which foreign policy decisions occur.