Лернер индексі және нарық билігі: деректер мен талдау

Measure of firm's market power
The Lerner index, formalized in 1934 by British economist of Russian origin Abba Lerner, is a measure of a firm's market power.

It is very important to note that market power alone does not guarantee high profits, since profits depend on the ratio of average costs to price. A firm may have more market power than another firm, but still make less profit. As an example, let's compare an average supermarket and a convenience store operating in the same area. In supermarkets, the margin is usually 15 20%, and in convenience stores 25 30 %. This is due to the fact that supermarkets operate in a more competitive environment — during their operation, other outlets are also working at the same time to ensure a significant number of customers, it is necessary to offer attractive prices. Convenience stores charge a higher price than supermarkets because some of their customers fall at a time when there is not a large selection of outlets or for the sake of a minor purchase, it makes no sense to look for other options. The number of visitors to such stores is generally less dependent on prices than in supermarkets (less elastic demand). According to the Lerner coefficient, small stores have more monopoly power because they charge higher margins on the same product. But at the same time, such stores usually receive a much smaller amount of profit than a supermarket, since they have a much smaller sales amount, and the average unit cost is higher.

+ Lerner index of the Czech credit market Year Mean Median 2000 0.4438 0.5486 2001 0.5598 0.5455 2002 0.5723 0.5530 2003 0.6165 0.6089 2004 0.5430 0.5371 2005 0.5980 0.6163 2006 0.5673 0.5457 2007 0.5650 0.5739 2008 0.5109 0.5029 2009 0.3921 0.3289 2010 0.6742 0.6582
During the period 2000–2005 the Lerner index computed for the credit market slightly increased. It means that there was a slight decrease in competition. Then, during 2006–2009, there was a decrease in the Lernex index. In 2010 the Lerner index significantly increased. The mean of the Lerner index computed for the full sample is 53.58 %, which do not confirm either monopoly or perfect competition in the credit market of Czech Republic.

+ Lerner index of the Czech deposit market Year Mean Median 2000 0.5905 0.6898 2001 0.6864 0.6959 2002 0.6930 0.6692 2003 0.7170 0.7204 2004 0.6595 0.6482 2005 0.6955 0.7100 2006 0.6718 0.6806 2007 0.6696 0.6776 2008 0.6255 0.6328 2009 0.5266 0.4880 2010 0.7642 0.7355
This table represents the estimation of the market power in the deposit market in Czech Republic. During the period 2005–2009 the Lerner index computed for the deposit market slightly decrease, which means a slight increase in competition. In 2010, there was an increase in the Lerner index. It signals a decrease in competition. However, the value of Lerner index haven't changed significantly in estimated 10 years.