A market which firms can enter if they choose and exit without losing money invested is

Gold is sold in world markets, usually priced in terms of troy ounces. In the market for gold, the price elasticity of demand for gold would be expressed as

A) the number of troy ounces of gold sold. B) the number of whatever currency is used in purchasing the gold. C) the number of dollars spent on gold. D) a unitless number.

Refer to Scenario 1.2 below to answer the question(s) that follow.SCENARIO 1.2: A scientist wants to understand the relationship between automobile emissions and the level of global warming. The scientist collects data on the volume of automobile emissions and the levels of global warming over time. The scientist concludes that a 1% increase in automobile emissions causes a 0.0003% increase in average global temperatures. From this information he concludes that the automobile emissions are harmful to the environment and should be reduced to stop the increase in global temperatures.Refer to Scenario 1.2. The statement that a 1% increase in the automobile emissions causes a 0.0003% increase in average global temperatures is an example of

A. positive economics. B. normative economics. C. the fallacy of logic. D. marginal economics.