• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.1
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• pp.7-15
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• 2020

It is a general phenomenon for manufacturers to provide vertically differentiated product line for more profit through improved market coverage. For such manufacturers, the compatibility between vertically differentiated products is an important decision issue. Some manufacturers provide full compatibility between high and low version products, whereas some provide only downward compatibility for the purpose of recommending high version product. In this study, the two representative compatibility strategies, full or downward, between vertically differentiated products produced by a single manufacturer are analyzed, especially under network externality and in the viewpoint of profit maximization. To do this we used a market model which captures the basic essence of vertical differentiation and network externality. Based on the proposed market model, the profit maximizing solutions are derived and numerically analyzed. The results can be summarized as follows : (1) Regardless of compatibility strategy, under network externality, vertical differentiation is always advantageous in terms of profit. (2) The full compatibility strategy is shown to be the most advantageous in terms of profit. In addition, it is necessary to make quality difference between differentiated products as wide as possible to maximize profit. (3) To gradually drive low version product out of the market and shift the weight pendulum of market to high version product, it is shown that the downward compatibility strategy is essential. Unlike intuition, however, it is also shown that in order to drive low version product out of market, it is necessary to raise the quality of the low version product rather than to lower it.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.159-166
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• 2018

The proliferation of information technologies made it possible to produce information products of different versions at much lower cost comparing to traditional physical products. Thus it is common for information product manufacturers to consider vertically differentiated product line for more profit through improved market coverage. Another salient characteristic of most information product is network externality. Existing researches dealing with vertical differentiation and network externality usually assumed oligopolistic market where vertically differentiated products are provided by competing companies, respectively. Moreover, they analyzed the essentially dynamic characteristic of network externality statically. In this study, different from the previous researches, the vertical differentiation strategy of a monopolistic company under network externality is dynamically analyzed. We used a two-period model to accommodate the dynamic feature of network externality. Based on the two-period model, the profit maximizing solutions are analyzed. The results showed that a monopolistic company has no incentive to differentiate products vertically when the network externality is absent. On the contrary, when the network externality exists, the monopolistic company can derive more profit by vertically differentiating the product line. It is also shown that, for more profit, the monopolistic company should keep the quality difference between the high quality product and the low quality product as greater as possible.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.2
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• pp.31-39
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• 2015

In this paper, we study the bargaining strategy of a distributor who sells vertically differentiated, i.e. high and low brand products. We derive and analyze the equilibrium solutions for both simultaneous and sequential bargaining games among the distributor, the high brand product manufacturer and the low brand product manufacturer. The result shows that the optimal bargaining strategy for the distributor heavily depends on the relative quality and price level of the low brand product comparing to those of the high brand product. It is also shown that, for more bargaining profit, the distributor has strong motivation to prefer a low brand product which has lower quality level per unit price.

• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.3
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• pp.107-120
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• 2011

The increased availability of store brand suppliers now provides retailers with opportunities to create their own lines of vertically differentiated multiple store brands within a product category. As the number of store brands increase, the retailer's shelf space becomes more crowded, which may force the retailer to consider dropping some national brands from its assortment. Despite these trends, the problem of product line design in a vertically differentiated product category has been analyzed mainly from a manufacturer's perspective in the marketing literature and it is not known to what extent the findings of the existing product line design literature provide applicable strategic guidelines for the new problem faced by retailers. In this study, we address this deficiency in the literature and conduct an in-depth study of the retailer's strategic design of a line of store brands and its assortment decision within the context of retail category management. We analyze the retailer's decision about not only how to design a line of store brands but also which national brand to drop from its assortment. The results of our analysis are as follows. First, if the retailer has to drop one of national brands from its assortment, it is the best for the retailer to drop the low-quality national brand rather than the high-quality national brand. Second, the retailer has to position the high-quality store brand relatively close to the high-quality national brand, remained on its shelf, in terms of quality so as to maximize the size of retail margin from the national brand. On the other hand, the retailer should set the quality of the low-quality store brand at a lower level than that of the low-quality national brand to increase the total category demand by attracting more price sensitive consumers. By doing so, the retailer can also minimize cannibalization between two store brands. Lastly, our analysis shows that the introduction of a line of store brands improves consumer welfare by increasing real values of all products on the shelf.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.2
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• pp.1-8
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• 2019

Network externalities are essentially dynamic in that the value consumers feel about a product is affected by the size of the existing customer base that uses that product. However, existing studies on network externalities analyzed the effects of network externalities in a static way, not dynamic. In this study, unlike previous studies, the impact of network externalities on price competition in a vertically differentiated market is dynamically analyzed. To this end, a two-period duopoly game model was used to reflect the dynamic aspects of network externalities. Based on the game model, the Nash equilibria for price, sales volume, and revenue were derived and numerically analyzed. The results can be summarized as follows. First, if high-end product has strong market power, the high-end product vendor takes almost all benefits of the network externality. Second, when high-end product has strong market power, the low-end product will take over most of the initial sales volume increase. Third, when market power of high-end product is not strong, it can be seen that the effects of network externalities on the high and low-end products are generally proportional to the difference in quality. Lastly, if there exists a strong network externality, it is shown that the presence of low-end product can be more profitable for high-end product vendor. In other words, high-end product vendor has incentive to disclose some technologies for the market entrance of low-end product, even if it has exclusive rights to the technologies. In that case, however, it is shown that the difference in quality should be maintained significantly.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.1
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• pp.37-44
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• 2021

The information products dramatically reduce the production costs of vertically differentiated products. Information products are also more likely to be affected by network externalities. Thus the proliferation of digital products is increasing the interests in network externality and vertical product differentiation. In step with this trend, the impact of network externalities on price competition in vertically differentiated markets has been continuously studied. Existing studies related to this topic have assumed that network externalities increase consumers' willingness to pay per unit quality. The results show that higher quality products are affected more by network externality. However, network externality is essentially a concept affected by the size of the consumer, not a concept associated with quality. In this work, unlike previous studies, we present a new market model that reflects the essential definition of network externality. Based on the proposed market model, we derive both simultaneous and sequential Nash equilibria and analyze them numerically. The main results obtained from the analysis can be summarized as follows. First, network externalities primarily increase the demand for low-quality products and have a secondary impact on the demand for high-quality products. Second, the larger the quality difference between products, the more profitable they are. It also has been shown that sequential pricing methods are more advantageous in terms of revenue than simultaneous pricing method.

• Environmental and Resource Economics Review
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• v.13 no.1
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• pp.133-160
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• 2004

This paper analyzes the long-run effects of an environmental tax levied on motor vehicles. If the government charges their consumers the tax as much as the monetary value of the external damage due to the pollutants emitted from motor vehicles, the operation of vehicles is reduced to the socially optimal level, alike to ordinary Pigouvian taxes. Thus, air pollution abatement is realized in the short run. Moreover, in the long run, the tax leads the consumers to prefer cleaner vehicles owing to the tax burden, and so the firms produce the motor vehicles with less pollutants emitted to meet the change of demand. Therefore, the tax has the additional effect on air pollution abatement. This result is obtained from the simulation in the oligopoly model which has an interior solution when the vehicles are horizontally and vertically differentiated.