Explain below economics concepts Only From articles or news events just 3 to 5 concepts no more than, give references mandatory these articles must be published after 5th January 2021 academic articles that do not even mention economics, but you can recognize economics. Give article reference and website link

List of concepts that you can find articles to explain: Discuss any two or 3 following concepts with references to articles.

1) Principle 1: People face tradeoffs

2) Principle 2: Opportunity Cost: The cost of something is what you give up to get it

3) Principle 3: Rational people think at the margin

4) Principle 4: People respond to incentives 5) Principle S: Trade (or Specialization) can make everyone better off

6) Principle 6: Markets are usually a good way to organize economic activity

7) Principle 7: Governments can sometimes improve market outcomes 8) The production possibilities frontiery

9) Absolute advantage

10) Comparative advantage 11) Demand curve: a change in the price of the good itself

12) Demand curve: a change in income: normal good 13) Demand curve: a change in income: inferior good

14) Demand curve: a change in the prices of related goods: substitutes

15) Demand curve: a change in the price of related goods: complements

16) Demand curve a change in the number of buyers 17) Demand curve: a change in tastes and preferences.

18) Demand curve: a change in buyers' expectations

19) Supply curve: a change in the price of the good itself

20) Supply curve: a change in input prices 21) Supply curve: a change in technology

22) Supply curve: a change in sellers' expectations 23) Supply curve: a change in the number of sellers

24) A market equilibrium

25) A market surplus 26) A market shortage

27) The price elasticity of demand 28) The price elasticity of supply

29) The income elasticity of demand

30) The cross-price elasticity of demand

33) A price ceiling 32) A price floor

33) A tax on buyers and/or sellers

34) Consumer surplus

35) Producer surplus 36) The benevolent social planner and total surplus

37) Efficiency-allocating resources to maximize total surplus 38) Equality-allocating resources uniformly

39) Market failure

40) An externality (either positive or negative) and the attempt to resolve it

41) Chapter 13 Table 3: Two of the many types of costs 42) Profit maximization in a competitive firm

43) Sunk cost 44) Monopoly

45) Price discrimination

46) Oligopoly,