Observers have suggested that adding sources of interpretation tends to increase interpreter discretion. The idea is embedded in a quip, attributed to Judge Harold Leventhal, that citing legislative history is like “looking over a crowd and picking out your friends.” Participants in debates over interpretive method have applied the idea to the proliferation of other sources as well, including canons of construction and originalist history. But the logic of “more sources, more discretion” has escaped serious testing. And predicting the effect of source proliferation is not a matter of logic alone. The empirical study of how information loads affect behavior has grown dramatically in recent decades, though almost without notice in legal scholarship on interpretive method.
This Article tests the logic and evidence for “more sources, more discretion.” The idea turns out to be incorrect, without more, as a matter of logic. Adding sources tends to reduce the chance of discretion using a simple model of interpretation. This starter model depicts judges as aggregators of source implications, and it draws on basic probability theory and computer simulations to illustrate. The analysis does change if we allow judges to “spin” or “cherry pick” sources, but without much hope for limiting discretion by limiting sources. Of course, judges will not always behave like machines executing instructions or otherwise follow the logic of these models. Thus the Article goes on to spotlight provocative empirical studies of information-load effects, develop working theories of interpreter behavior, and present new evidence.
After emphasizing that interpreters might ignore additional information at some point, the Article tests three other theories. First, an extended dataset casts doubt on an earlier study that linked a growing stock of precedents to increased judicial discretion. Adding to the pile of precedents seems to have no simple pattern of effect on discretion. Second, existing studies indicate that increasing information loads might prompt judges to promote the status quo, and new data suggest that this effect depends on the type of information added. The number of sources cited in appellant briefs appears to have no effect on judges’ willingness to affirm—in contrast with the number of words and issues presented, which may have opposing effects. Third, an expanded dataset supports an earlier finding that judges who face a large number of doctrinal factors might weight those factors in a quasi-legal fashion. This time-saving prioritization does not seem to follow conventional ideological lines.
With simple intuitions in doubt, thoughtful work remains to be done on the effects of source proliferation. Observers interested in judicial discretion have good reason to look beyond source proliferation to find it. And observers interested in institutional design have good reason to rethink the range of consequences when information is added to our judicial systems.
