Final answer:
Both Canada and the United States have high GDPs due to the rise of the service sector, a shift towards technology and innovation-based economies, the primary industries of natural resources, and for the U.S., a relatively lower dependence on exports due to its large economy.
Step-by-step explanation:
The gross domestic product (GDP) of Canada and the United States has been influenced by several factors. In Canada, the rise of the service sector now employs roughly three-quarters of Canadians and generates over 60 percent of the GDP. Although Canada is traditionally known for its primary industries like agriculture, fishing, mining, energy, and forestry, there has been an economic shift towards manufacturing, with a focus on innovation and technology, where industries such as biotechnology and information technology are thriving. Equally important is Canada's close trade relationship with the United States, with a large proportion of its exports going to its southern neighbor.
The United States, having a large economy, has an export/GDP ratio well below the global average. This is attributed to its ability to contain more of the division of labor within its own borders. However, it is notable that in recent decades, the export/GDP ratio has generally risen, indicating a slight increase in globalization's influence on the U.S. economy. Additionally, the knowledge-based sector and advanced manufacturing are significant contributors to the high GDP of the U.S., although it is less dependent on trade compared to smaller economies.