Persuasive authority using other jurisdiction&#39;s opinions
<p>I'm an English teacher who teaches legal English to foreign students using the UK legal system for context. I was checking the definition of 'Persuasive authority' using TransLegals' dictionary and part of the definition stood out to me.</p>

<blockquote>
  <p><em>persuasive authority, noun</em></p>
  
  <p>legal writings that may help guide a court in reaching a decision,
  but which are not binding. Examples of persuasive authority include
  opinions from lower courts, <strong>opinions from courts in other
  jurisdictions</strong>, comments made by higher courts as obiter dicta things
  said in a judgment that are not essential to the decision and which
  are not binding precedent, dissenting judgments and articles from
  legal journals</p>
  
  <p>The court noted the lack of either binding or persuasive authority on
  the issue but considered certain cases which provided guidance.</p>
</blockquote>

<p>I would like to know which jurisdictions would be considered. Would a Magistrates court use rulings only in the UK? Include other common law systems such as USA, Canada etc? Or even include civil law rulings abroad?</p>

<p>A common law court can use <em>any</em> common law jurisdictions as a source of persuasive authority. </p>

<p>In practice, the closer (in both legal and cultural terms) a jurisdiction is the more likely it is to be used because a) common law <em>drifts</em> over time and B) legislators change it in different ways. For example, the Australian states and Canadian provinces will look to each other far more often than they will look abroad and both will tend to look to England/Wales before looking at each other or say India. </p>

<p>Because the United States legal tradition separated more than a century earlier than the rest of the common law jurisdictions and remained more conservative than England/Wales (e.g. the retention of grand juries and jury trials for civil cases) the law there has more limited application outside the US and vice versa: they are just too different.</p>

<p>Persuasive precedent is generally only applicable for the interpretation of new laws - long standing laws usually have plenty of binding precedents. It is particularly common to look outside a jurisdiction for precedent when a piece of legislation is based on an existing one in another country courts will look to that jurisdiction for case law.</p>

<p>For example, the New South Wales <em>Building and Construction Industry Security of Payment Act 1999</em> is based on a similar law in Alberta, Canada and the first cases under this act looked to Albertan case law for precedent. However, when Queensland enacted a similar law in 2004, their case law all looked (and sometimes still does - prior to recent amendments in both jurisdictions the non-administrative provisions were almost word-for-word the same) to NSW.</p>

legal-terms jurisdiction precedent