This article discusses a new study that shows rising levels of equality do not necessarily result in lower crime, or health. On the contrary, it shows that higher inequality is associated with higher growth. However, the author argues that extreme levels of poverty should be combatted, and that economic policy should be used to promote "human exceptionalism."

This demonstrates economic activity because it focuses on the performance of an industry in the economy and is therefore a component of GDP. The article also evaluates what is likely to happen in the future of the industry, and the expected consumption patterns of certain individuals.

This is an externality of production because the air pollution from the buses imposes an unpaid social cost upon society; the article then discusses how the government plans to fine people to deter this activity and raise revenue.

This article is about how the Indian government is going to end its drug control policy. By keeping the "anti-competitive" policy, the Indian government has been artificially keeping the supply of drugs low.

This is an example of an excise tax because it is a tax on products that aren't environmentally friendly and the article mentions that there is political pressure to put the ecotax "on the shelf" so consumers can make better decisions. 

This shows price elasticity, because despite the fact house prices keep rising, people keep buying them for eleven straight months.

This article demonstrates the concept of equilibrium by pointing out that there is a shortage of sugar in Europe because the EU is trying to shrink the sugar industry. The shortage of sugar means there's excess demand; the supply is insufficient because of certain trade barriers and import duties. 

This article shows how resources are allocated in a free market by pointing out that both the quantity demanded and demand for gasoline fell. The quantity demanded fell because of a higher price; demand is falling because of uncertainty (which pushes the demand curve to the left). This shows allocative efficiency because if fewer people are working it make sense that fewer people are driving because these people no longer have to drive to work. Furthermore, these people may not have the ability to drive as much anymore because of their lower income.

This article demonstrates opportunity cost because it shows that eating healthy food costs less but most people prefer not to because of the inconvenience of cooking it.

This article demonstrates opportunity cost because a rise in government revenues may lead to a shortfall in private sector investment.

This article demonstrates opportunity cost by saying that by selling short term treasuries, which will lower their price, and buying long term treasuries, which will raise their price, there will be benefits for banks with mortgages on their balance sheets.

This demonstrates scarcity by showing that a shortage of drugs, caused by manufacturing problems, is causing high markups from secondary suppliers.