This is a follow-up to the previous post regarding the paper Andrew Green and I recently posted on SSRN.  The point of this post is to elaborate on the motivation for the paper and summarize our results.

The debate: There is an active debate surrounding the desirability of a more open appointments process for Supreme Court of Canada justices. On the one side of the debate are those militating for more openness, transparency, and public input into the selection of justices for the Court. The argument is that since the decisions of the Court often have such wide-ranging social and economic effects—often not reversible by Parliament or legislatures (other than temporarily through the use of the notwithstanding clause)—there should be a role for democratic input into the selection of justices. Typically the envisioned opening of the process would involve Parliamentary scrutiny and vetting of nominees, with the aim of exposing and testing the policy inclinations of would-be justices. On the other side of the debate are those who fear that Parliamentary involvement in the selection of justices would threaten judicial independence and politicize the selection of justices in ways that the process has avoided in the past. Further, opponents of a Parliamentary process fear that strong candidates that would otherwise be willing to consider an appointment might refuse in order to avoid putting their personal lives before a national audience and to avoid the unpleasantness of aggressive questioning by Parliamentarians who are keen to score political points.

The common assumptions: One of the central assumptions underlying the debate about appointments to the Supreme Court of Canada is that it is possible to know “the policy preferences” or “ideology” of a prospective justice before they are appointed. After all, if Prime Ministers cannot easily determine ex ante how a particular justice is likely to vote in politically divisive appeals, then it would seem that the hopes of those in the first camp of exposing and testing nominees’ political preferences are fanciful. A further assumption is that justices come “pre-loaded” with a certain policy orientation, and that this policy orientation does not (or is unlikely to) change over time.  In other words, there is an assumption that justices will have unwavering, constant policy preferences. This assumption is important because even if a justice’s policy preferences can be known at the time of appointment, this information may be of only short-run relevance if the views of justices are subject to continuous revision, refinement and change.

Our contribution: These assumptions give rise to a number of empirical questions. Are a justice’s policy preferences correlated with the party of the Prime Minister who appointed them or with newspaper descriptions of their dispositions at the time of appointment? Is judicial behaviour more predictable in their first year on the bench than in later years? Do justices’ policy preferences change over time? If so, is there a common or predictable pattern as to how justices change?

Over a justice’s career: Using two different methodologies (a direct methodology in which certain votes are labeled “liberal” and others “conservative”, and one indirect where we let the votes of the justices themselves reveal where their latent “ideal points” are in a linear policy space), we find that overall there is a modest relationship between the party of the appointing Prime Minister and a justice’s subsequent voting record and revealed ideal points. In some specifications, the result was statistically significant, and in others it was not. Even where the results were significant in statistical terms, however, the substantive difference was relatively small (e.g. a 5% difference in “liberal” voting behaviour). Even among justices appointed by the same Prime Minister there are dramatic differences; for example, Brian Mulroney appointed both the most “liberal” justice and the most “conservative” justice, as identified by the indirect methodology. Similarly, Pierre Trudeau appointed the second most extreme justices on the Court according to the indirect methodology. Thus, the overall results of a slight correlation disguise a huge amount of variation among the individual justices. In addition, also using the direct and indirect methodologies, we find that there is surprisingly little correlation between the predictions of judicial policy orientation as contained in newspaper editorials from the time of a justice’s appointment (as reported by Ostberg and Wetstein in Attitudinal Decision Making in the Supreme Court of Canada, UBC Press, 2007) and a justice’s subsequent voting behaviour. Our results suggest that both Prime Ministers and journalists alike find it difficult to pigeon-hole would-be justices at the time of their appointment from a long-term perspective. Expectations of how they will vote just do not match up particularly well with how they do in fact vote over the long-run.

In a justice’s first term on the Court: We suspected that focusing on whether a justice’s entire career of voting on the Court might be misleading, since judicial decision-making may prove to be more predictable at the start of a justice’s tenure on the Court. To test this, we looked at the correlation between the party of appointing Prime Minister and a justice’s votes in his or her first year on the Court. We found that there was a modest correlation using the direct methodology counting all appeals, the subset of criminal appeals, and in the subset of non-criminal Charter appeals. The result was statistically significant only in criminal appeals using the direct method at the 90% level of confidence, but not in any of the other specifications. The correlation was also modest between the newspaper scores and voting in the first year in criminal appeals. In non-criminal Charter cases, however, there was a negative correlation between the newspaper scores and judicial votes. There were also negative correlations between the ideal points of justices in their first year on the Court and the newspaper scores. Taken together, there is little evidence that justices are more predictable in their first year on the Court than they are in later years.

Changes in policy preferences over time: Drawing on two similar direct and indirect methodologies, we show that judicial policy preferences shift over time—sometimes significantly. These preference changes are not predictable. Some justices become more “conservative”, some become more “liberal”, some stay constant, and some exhibit other patterns (for example, Justice (now Chief Justice) McLachlin appears to have started out as a “liberal” justice when she first joined the Court in 1989, become more “conservative” beginning in the early 1990s, and has returned to a more “liberal” approach in recent years).

The bottom-line: Of course, all we can show in our study is that this has been true of the justices who served from 1982-2004. Justices appointed under another system or in another time might well exhibit other traits or inclinations. With this caution in mind, however, the net result of the empirical analysis is this—despite some notable exceptions, most particularly Justice L’Heureux-Dubé, the justices of the Supreme Court of Canada do not, by and large, vote in ideologically predictable ways either in the short-term or on a long-term basis. In addition, their policy preferences are in a constant state of change; at any given time some justices will be changing little, others will be moving in a more “liberal” direction, and others will be tending towards a more “conservative” approach. This suggests that the debate surrounding the appointments process should not assume naively that would-be justices have certain observable, immutable ideologies. In addition, any claim that the obscure and relatively secretive appointments process that has predominated in the post-Charter era has produced justices that are keenly indulging ideological inclinations has been seriously undermined by our results.