Final answer:
The standard patent length agreed upon by nations across the world is typically 20 years, which aims to allow inventors to earn a return while preventing perpetual monopolies.
Step-by-step explanation:
The nations of the world have generally agreed upon a standard patent length of 20 years. This time frame is intended to strike a balance, allowing the inventor to make a satisfactory financial return without enabling a permanent monopoly price.
However, there are some criticisms and considerations to this system, such as the speed of technological advancement in industries like biotechnology and semiconductor design, where innovation can render a patent less relevant quickly. Furthermore, not everything can be patented, and there's a risk of patents being too extensive or granted too easily, as evidenced by the case of Xerox in the 1970s.