N-firm Concentration Ratios

The table shows the global sales of PCs by company in 2015. Calculate the 5 firm concentration ratio

• 78.77%

• 68.75%

• 61.68%

• 59.65%

The following table shows sales of tablets in Quarter 2 and Quarter 3 in 2013. From this data it can be deducted that the tablet market is

• monopolistically competitive

• perfectly competitive

• oligopolistic

• a natural monopoly

The following table shows sales of tablets in Quarter 3 2012 and Quarter 3 in 2013. The 3 firm concentration ratio in Quarter 3 2012 was 59.20%. Calculate the 3 firm concentration ratio in quarter 3 2013.

(a)  

The table gives the 4-firm concentration ratio in a selection of industrial sectors in the USA. What can be inferred from the information?

• The metal household furniture sector is more concentrated than the breakfast cereal sector

• There are no barriers to entry in food manufacturing

• There are external diseconomies of scale in the motor vehicle manufacturing

• Four firms have significant power in motor vehicle manufacturing

• The guided missile and space vehicle sector is monopolistically competitive

The attached pie chart shows market share in the UK grocery industry in 2009. Which of the following statements is true for the UK grocery market.

• It is monopolistically competitive

• It has a low concentration ratio

• The 4-firm concentration ratio is 75.6%

• It is perfectly competitive

• The 3-firm concentration ratio is 60.4%

The following chart shows the percentage market share of the US airline industry in 2006. From the information it can be deduced that:

• The four firm concentration ratio is 64.5%

• The US airline industry is monopolistically competitive

• The US airline industry is highly concentrated

• The US airline industry in a natural monopoly

• There are low sunk costs in the US airline industry