In the Parsons case (text, p. 409), the JCPC breathed life into the federal power over trade and commerce, vested to Parliament by section 91(2) of the Constitution Act, 1867. The Board explained that this power comprised two elements: the power over international and interprovincial trade; and general regulation of trade affecting the whole country. The JCPC attempted to set limits on the trade and commerce power. Without these limits, the words describing the trade and commerce power could potentially be "in their unlimited sense ... sufficiently wide ... to include every regulation of trade". Subsequent cases continued to put constraints on the trade and commerce power.

In the Insurance Reference, [1916] 1 A.C. 588, the JCPC refused to uphold federal jurisdiction over insurance merely because the industry spanned the country. That the industry "spanned the whole country", was noted, but, Viscount Haldane nevertheless laid down that, "the authority to legislate for the regulation of trade and commerce does not extend to the regulation by a licensing system of a particular trade."

The jurisprudence has wrestled with the meaning of provincial power to regulate particular trades. One of the more interesting, and troubling, delimitatings of this concept occurred in the 1957 Ontario Farm Marketing Reference at p. 413 of Constitutional Law of Canada, 8th edition. The rich expositions of the judges in this case were developed further in the remainder of cases in the textbook. These expositions led to the proposition that the power to regulate trade and commerce does extend to products produced by those particular trades "once an article enters into the flow of interprovincial or external trade" (1957 Reference, at 415 text). The tension between these two concepts are illustrated in the remainder of the cases in the textbook.

The provincial competence to regulate local trades flows primarily from provincial jurisdiction over property and civil rights in s. 92(13). Provincial jurisdiction over property and civil rights embraces all private law transactions. These include virtually all commercial transactions. As was the case in sculpting limits for federal jurisdiction over trade and commerce, the Courts established boundaries on provincial regulatory authority over local trades. Property and civil rights as so delimited include rights arising from contract (Citizens Insurance); certain powers to prevent crime (Bedard v. Dawson); powers to control transactions taking place wholly within the province, even if the products themselves are imported (Caloil v. AG Canada); and generally, the power to regulate provincially-incorporated businesses. The fact that the exercise of such powers has an incidental effect on a federal sphere of influence does not, by itself, change the true nature of the regulation as provincial regulations AG Quebec v. Kellog. Moreover, the fact that a valid provincial regulation may affect an export trade or the cost of doing business is similarly not conclusive of determining whether it is made "in relation to" the regulation of property and civil rights (Carnation v. Quebec Agricultural Marketing Board).

The question thus arises, if a provincial legislation affects rights of individuals outside the province, can the legislation really be said to affect property and civil rights "in the province"? Ladore v. Bennett would seem to indicate that if the legislation is, in pith and substance, provincial, ancillary effects on the rights of individuals outside the province are irrelevant. Churchill Falls confirms this proposition. But, where the provincial legislation is, in pith and substance, legislation in relation to the rights of individuals outside the province, it will be ultra vires the province. As Ruth Sullivan points out at pp. 337-338 of the text, the lines become blurred where the rights being affected are contractual rights, which have no obvious situs.

Part of the problem may be that the Courts are striving too hard to find a physical situs . In Ladore, Royal Bank, Interprovincial Coops, Churchill Falls, and Hunt, the Court seeks to sculpt the rules for locating the legal relationships in the image of private international law. This is strange, considering that the values of constitutional law are different than those of private international law. A thesis of this section is that rules for situating legal relations in light of the territorial limitation on provinces in s. 92(13) should be constitutional rules. The guiding value ought to be whether the province advances a sufficient "sphere of interest" to undergird the assertion of provincial legislative jurisdiction. This is a concept I look forward to exploring with students in the class.

In addition to materials contained in Constitutional Law of Canada, 8th edition, the following links might be of some interest:

• Canadian Egg Marketing Agency - what all those marketing cases were about
• General Motors v. CN Leasing
• Hunt v. T&N plc
• Morguard Investments v. De Savoye