The research used informatics software and CanLii data to analyze how often, and in which contexts, cases have been cited in court decisions.
It found that 19 per cent of Supreme Court of Canada decisions were still important after 15 years, “where importance is defined as a positively trending pattern of citation.”
For all other jurisdictions, less than four per cent of cases remained important after 15 years.
The seemingly low figure is due to the “high volume of perfunctory decisions” from provincial courts that may be fact specific, says report author Thom Neale.
Neale is a web developer who previously worked as a legal editor at the New York State Court of Appeals, where his work involved checking citations found in written decisions. He says the results of the study confirmed his feelings that “a large majority of cases fall into mediocrity immediately and are never really cited.”
But the large number of cases without much long-lasting impact doesn’t necessarily reflect badly on the justice system, he says.
“A case with similar facts might come up and [make] a former case irrelevant,” he explains.
The study also found the lower courts of smaller jurisdictions issue decisions that have as lasting an impact as those from appellate courts in much larger jurisdictions.
Decisions in less populous jurisdictions probably survive longer on average because “the overall volume of newly issued law is much lower in those jurisdictions, leading courts and practitioners to cite older decisions with greater frequency and duration,” states the report.
The study lists the top 100 cases that continue to be cited over time. No. 1 is R v. Manninen, a 1987 case which established standards for determining whether an erroneous jury charge in a criminal trial is grounds for reversal.
“Many of these enduring cases appear to be cited for uncontroversial legal rules that are procedural or at least quasi-procedural in nature,” says the report.
CanLii commissioned the study. CanLii president and chief executive officer Colin LaChance says the data will be used in a web application due to be released at a hackathon event next Friday and Saturday in Ottawa.
The app will allow lawyers and courts to “dig deeper” into the “longevity” of citations, he says, allowing them to see when a case was most influential and when this influence tailed off.
“It could be an indication that it was overruled or there was some new precedent,” he adds.
CanLii will also take account of the information when deciding which areas to expand into. However, this is also likely to be heavily influenced by resources. For example, CanLii has added thousands of Newfoundland cases, and historical Alberta cases going back to 1971, to its database, with funding from provincial law foundations and courts.