Change in demand and change in quantity demanded are key concepts in economics. The former involves shifts due to changes in factors like income or consumer preferences, whereas the latter is caused by price changes and results in movement along the demand curve.
In economics, the income effect refers to the change in purchasing power and quantity demanded of goods due to a change in consumers' real income resulting from a price change.
Speculation is the purchase of any property or security with the expectation of obtaining a quick profit as a result of price change, possibly without adequate research. It is often compared to gambling but is different from investment.
The substitution effect in economics refers to the change in consumption patterns due to a change in the relative prices of goods. When the price of a good decreases, consumers are more likely to substitute it for other goods, increasing their consumption of the now cheaper good. Conversely, when the price of a good increases, consumers will tend to switch to substitutes that have become relatively cheaper.
