Differentiated Products Industries Research Articles

Empirical Models of Demand and Supply in Differentiated Products Industries

This is an invited chapter for the forthcoming Volume 4 of the Handbook of Industrial Organization. We present empirical models of demand and supply in differentiated products industries with an emphasis on the key ideas arising from the recent applied literature. We start with a discussion of the challenges in modeling and estimation of demand for differentiated products, and focus on discrete choice characteristics-based demand models that address these challenges while allowing enough flexibility to capture realistic substitution patterns. Our discussion emphasizes how empirical strategies can leverage different features of data depending on the sources of variation that are commonly found in applied work. Moving to the supply-side, we show how demand estimates combined with a pricing model, can be used to recover markups and marginal costs. We also show how the model of pricing can be tested. We discuss a baseline Bertrand-Nash model of competitive pricing, and expand it to cover a) coordinated pricing, b) wholesale relationships, and c) bargaining. We end the chapter with extensions of the demand model, including dynamic and continuous demand.

Estimating Production Functions in Differentiated-Product Industries with Quantity Information and External Instruments

This paper develops a new method for estimating production-function parameters that can be applied in differentiated-product industries with endogenous quality and variety choice. We take advantage of data on physical quantities of outputs and inputs from the Colombian manufacturing survey, focusing on producers of rubber and plastic products. Assuming constant elasticities of substitution of outputs and inputs within fi rms, we aggregate from the fi rm-product to the firm level and show how quality and variety choices may bias standard estimators. Using real exchange rates and variation in the bite of the national minimum wage, we construct external instruments for materials and labor choices. We implement a simple two-step instrumental-variables method, fi rst estimating a difference equation to recover the materials and labor coeffcients and then estimating a levels equation to recover the capital coeffcient. Under the assumption that the instruments are uncorrelated with fi rms' quality and variety choices, this method yields consistent estimates, free of the quality and variety biases we have identif ed. Our point estimates differ from those of existing methods and changes in our preferred productivity estimator perform relatively well in predicting future export growth.

Estimating Production Functions in Differentiated-Product Industries with Quantity Information and External Instruments

This paper develops a new method for estimating production-function parameters that can be applied in differentiated-product industries with endogenous quality and variety choice. We take advantage of data on physical quantities of outputs and inputs from the Colombian manufacturing survey, focusing on producers of rubber and plastic products. Assuming constant elasticities of substitution of outputs and inputs within firms, we aggregate from the firm-product to the firm level and show how quality and variety choices may bias standard estimators. Using real exchange rates and variation in the bite of the national minimum wage, we construct external instruments for materials and labor choices. We implement a simple two-step instrumental-variables method, first estimating a difference equation to recover the materials and labor coefficients and then estimating a levels equation to recover the capital coefficient. Under the assumption that the instruments are uncorrelated with firms' quality and variety choices, this method yields consistent estimates, free of the quality and variety biases we have identified. Our point estimates differ from those of existing methods and changes in our preferred productivity estimator perform relatively well in predicting future export growth.

Quantifying the coordinated effects of partial horizontal acquisitions

Recent years have witnessed an increased interest, by competition agencies, in assessing the competitive effects of partial acquisitions. We propose an empirical structural methodology, which can deal with settings involving all types of owners and ownership rights, to quantify the coordinated effects of partial horizontal acquisitions on differentiated products industries, by evaluating the impact of such acquisitions on the minimum discount factors for which coordination can be sustained. We also provide an empirical application of the methodology to several acquisitions in the wet shaving industry that give rise to cross- and common-ownership structures. The results are as follows (i) the incentives to coordinate of the firms that the acquiring party is – pre-acquisition – able to influence are non-decreasing with any acquisition; (ii) the incentives to coordinate of the acquired firm are non-decreasing with acquisitions involving full or partial both financial and corporate control rights, but non-increasing with acquisitions involving full or partial solely financial rights; and (iii) the incentives to coordinate of the remaining firms in the industry are non-increasing with any acquisition. This implies that the coordinated effects of partial horizontal acquisitions are, in general, ambiguous, which illustrates the importance of an empirical structural methodology.

Eurotunnel versus the Ferries

Considers the competitive strategy of the Channel Tunnel just prior to the time it opened for business in 1994. Focusing specifically on the tunnel's Le Shuttle service for freight and passenger traffic, gives students an opportunity to explore whether Le Shuttle should follow a premium pricing strategy relative to the cross-channel ferries, match the ferries' prices, or undercut the ferries' prices. Following a section on the history of the tunnel's construction, provides an in-depth discussion of the cross-channel ferry business and the Le Shuttle services. Concludes by posing the question: What pricing strategy should Le Shuttle follow?To illustrate the key drivers of price competition in a differentiated products industry: differences in marginal cost; vertical differentiation among competitors; the degree of horizontal differentiation in the market; and the sources and sustainability of competitive advantage.

Learning versus sunk costs explanations of export persistence

This paper explores the role of sunk costs versus learning in explaining persistence in exporting. Multiple studies attributed such persistence to sunk market-entry costs. This paper shows that similar patterns of exporting are also consistent with a learning mechanism and finds a strong empirical support for such a mechanism in the context of Colombian plant-level data. Second, the paper empirically discriminates between the two competing theories, and finds that once learning is controlled for, the role of sunk costs in generating export persistence is at most forty percent of what is currently estimated in the literature. Finally, while in differentiated-products industries export persistence arises primarily due to learning, in the homogeneous-products industries such persistence arises primarily due to the sunk-cost mechanism.

Reliability Examination in Horizontal-Merger Price Simulations: An Ex-Post Evaluation of the Gap between Predicted and Observed Prices in the 1998 Hyundai-Kia Merge

Horizontal-merger price simulations, which rely upon pre-merger data to predict post-merger prices, have been proposed and used in antitrust policymaking. However, a dearth of closely observed large mergers in differentiated-product industries makes empirical investigations of simulation performance extremely difficult, and raises many questions regarding the accuracy of simulation performance. Although a handful of previous studies exist, they focus on short-term simulation performances and ignore long-run effects of mergers. This research investigates the long-run simulation performance and long-run pricing effects of merger in the Korean automobile industry for the period 1991–2010. This period saw the merger of Hyundai and Kia Motors in 1998, a merger caused by the Asian economic crisis and which resulted in the conglomeration of 70 percent of the Korean automobile market. By taking Nevo’s (2000, 2001) method as a base and measuring its performance against this real-world merger, I find that post-merger prices can be predicted reasonably well in the short term, but that large discrepancies appear in the long-run simulation. To account for this discrepancy, I confirm four further factors that appear essential to move toward a more accurate post-merger price simulation model: change in marginal costs, change in product lines, and change in consumer incomes and preferences. I counterfactually investigate each factor’s contribution to price change, confirming their significance. In my investigation I estimate consumer preferences and substitution patterns leading up to the merger, then I calculate marginal costs, and simulate post-merger prices. In addition, I estimate automobile assembly plant-level production functions to evaluate merger synergy effects. By incorporating changes in the four factors I mention, I can account for 61 percent of the long-run price discrepancy.

Measuring unilateral effects in partial horizontal acquisitions

Recent years have witnessed an increased interest, by competition agencies, in assessing the competitive effects of partial acquisitions. We propose an empirical structural methodology to examine quantitatively the unilateral impact of partial horizontal acquisitions. The acquisitions may be direct or indirect, and may or may not correspond to control. The proposed methodology simulates the effects on prices, market shares, firm profits and consumer welfare. It can deal with differentiated product industries and nest full mergers as a special case. We provide an empirical application to several acquisitions in the wet shaving industry.

Undercut-Proof Equilibria with Multiple Firms

This short article provides formulae for computing the undercut-proof equilibrium prices in a differentiated products industry with any finite number of firms. The formulae are very simple and can be easily implemented with a typical spreadsheet to solve for the unique equilibrium prices.

Measuring Unilateral Effects in Partial Acquisitions

Recent years have witnessed an increased interest, by competition agencies, in assessing the competitive effects of partial acquisitions. We propose an empirical structural methodology to examine quantitatively the unilateral impact of partial acquisitions involving pure financial interests and/or effective corporate control on prices, market shares,firm profits and consumer welfare. The proposed methodology can deal with differentiated products industries, with both direct and indirect partial ownership interests and nests full mergers (100% financial and control acquisitions) as a special case. We provide an empirical application to several acquisitions in the wet shaving industry.

Quantifying the Coordinated Effects of Partial Horizontal Acquisitions

The growth of private-equity investment strategies in which firms often hold partial ownership interests in competing firms has led competition agencies to take an increased interest in assessing the competitive effects of partial horizontal acquisitions. We propose a methodology to evaluate the coordinated effects of such acquisitions on differentiated products industries. The acquisitions may be direct and indirect, and may or not correspond to control. The methodology, that nests full mergers, evaluates the impact on the range of discount factors for which coordination can be sustained. We provide an empirical application to several acquisitions in the wet shaving industry.

Entry and pricing in a differentiated products industry: evidence from the ATM market

We estimate a structural equilibrium model of the automatic teller machine market (ATM) to evaluate the implications of regulating ATM surcharges. We use data on bank characteristics, potential and actual ATM locations, and consumer locations; identify the model parameters with a regression discontinuity design; and develop methods to estimate the model without computing equilibria. A surcharge ban reduces ATM entry 12% and consumer welfare 24% but increases firm profits 27%. Total welfare under either regime is 4% lower than the surplus maximizing level. The article can help shed light on the implications of unregulated entry for differentiated products industries.

Antitrust Evaluation of Horizontal Mergers: An Economic Alternative to Market Definition

We describe a simple initial indicator of whether a proposed merger between rivals in a differentiated product industry is likely to raise prices through unilateral effects. Our diagnostic calibrates upward pricing pressure (UPP) resulting from the merger, based on the price/cost margins of the merging firms' products and the extent of direct substitution between them. As a screen for likely unilateral effects, this approach is practical, more transparent, and better grounded in economics than are concentration-based methods.

Labour Market Rigidities, Trade and Unemployment

We study a two-country, two-sector model of international trade in which one sector produces homogeneous products and the other produces differentiated products. Both sectors are subjected to search and matching frictions in the labour market and wage bargaining. As a result, some of the workers searching for jobs end up being unemployed. Countries are similar except for frictions in their labour markets, such as efficiency of matching and costs of posting vacancies, which can vary across the sectors. The differentiated-product industry has firm heterogeneity and monopolistic competition. We study the interaction of labour market rigidities and trade impediments in shaping welfare, trade flows, productivity, and unemployment. We show that both countries gain from trade. A country with relatively lower frictions in the differentiated-product industry exports differentiated products on net. A country benefits from lowering frictions in its differentiated sector’s labour market, but this harms the country’s trade partner. Alternatively, a simultaneous, proportional lowering of labour market frictions in the differentiated sectors of both countries benefits both of them. The opening to trade raises a country’s rate of unemployment if its relative labour market frictions in the differentiated sector are low, and it reduces the rate of unemployment if its relative labour market frictions in the differentiated sector are high. Cross-country differences in rates of unemployment exhibit rich patterns. In particular, lower labour market frictions do not ensure lower unemployment, and unemployment and welfare can both rise in response to falling labour market frictions and falling trade costs.

Market Power, Multimarket Contact and Pricing: Some Evidence from the US Automobile Market

Multimarket contact is perceived to be one of those factors, which can facilitate and sustain implicit collusive (cooperative) arrangements. This paper attempts to develop new approaches to study the interdependence of firm behaviour across markets, especially in the context of differentiated products industries. I analyse the principle of conducting a test of the mutual forbearance hypothesis, and its application using particular data. The multimarket contact effects are studied within a structural oligopoly model for differentiated products for the US automobile market on the basis of the aggregate product-level data for 2001-2003. Some support has been found that multimarket contact may influence competition in the automobile market and increase the firms’ strategic interdependence. This effect is, however, difficult to disentangle from the effect of the market concentration in the US automobile market (dominance of the market by the American Big Three) on the firm behaviour, which could also facilitate collusion. In other words, it is difficult to argue whether coordination is due to market concentration, or due to multimarket contact, or both. Concentration is argued to foster the slack, which is transferred through the multimarket contact.

Antitrust Evaluation of Horizontal Mergers: An Economic Alternative to Market Definition

We describe a simple initial indicator of whether a proposed merger between rivals in a differentiated product industry is likely to raise prices through unilateral effects. Our diagnostic calibrates upward pricing pressure (UPP) resulting from the merger, based on the price/cost margins of the merging firms’ products and the extent of direct substitution between them. As a screen for likely unilateral effects, this approach is practical, more transparent, and better grounded in economics than are concentration-based methods.

Firm-level productivity studies: Illusions and a solution

Applied economists often wish to measure the effects of policy changes (like trade liberalization) or managerial decisions (like R&D expenditures or exporting) on firm-level productivity patterns. But firm-level data on physical quantities of output, capital, and intermediate inputs are typically unobservable. Therefore, when constructing productivity measures, most analysts proxy these variables with real sales revenues, depreciated capital spending, and real input expenditures. Our first objective is to argue that the resultant productivity indices have little to do with technical efficiency, product quality, or contributions to social welfare. Nonetheless, they are likely to be correlated with policy shocks and managerial decisions in misleading ways. Our second objective is to develop an alternative approach to inference. We assume firms' costs and revenues reflect a Bertrand–Nash equilibrium in a differentiated product industry, as in Berry [Berry, Steven (1994) “Estimating discrete-choice models of product differentiation,” Rand Journal 25(2), pp. 242–262.]. This allows us to impute each firm's unobserved marginal costs and product appeal from its observed revenues and costs. With these in hand, we calculate each firm's contribution to consumer and producer surplus. Further, we link these welfare measures to policy and managerial decisions by assuming that marginal costs and product appeal indices follow vector autoregressive (VAR) processes, conditioned on policy proxies and/or managerial choice variables. We estimate the demand system parameters and VAR parameters jointly using Bayesian techniques. Applying our methodology to panel data on Colombian paper producers, we study the relation between our welfare-based measures and conventional productivity measures. We find that the two are only weakly correlated with one another. Further, they give contrasting pictures of the relationship between firms' performances and their participation in foreign markets. One reason is that product appeal variation has little effect on standard productivity indices, but it is captured by welfare-based performance measures.

Intra-industry differences in vertical integration, heterogeneous costs and pricing: the case of web hosting

In many differentiated product industries, both traditional and “new economy” activities, vertically integrated firms also supply inputs to apparent rivals in the downstream business. This generates heterogeneity between low- and high-sunk cost suppliers with implications for entry and competitive conduct. The web hosting market is typical with primary suppliers operating alongside resellers who rent server space from them. We explore the impact of competition in US hosting using a unique dataset covering 15,000 packages offered by 3,500 firms. The results suggest price is sensitive to competitor clustering in quality space; an outcome consistent with easy entry for resellers with ultra-low fixed costs.

Monopolization Through Acquisitions in a Differentiated Product Industry

This article analyzes the incentive to merge in a context of price competition with horizontal product differentiation. In contrast to the results obtained by Kamien and Zang (1990), we show that merged equilibria can appear in this game. Moreover monopolization of the industry occurs with a high number of firms.

Exchange Rates and Cash Flows in Differentiated Product Industries: A Simulation Approach

ABSTRACTHow do exchange rate changes impact firms' cash flows? We extend a simulation method developed in industrial organization to answer this question. We use prices, quantities, and product characteristics for differentiated products, coupled with a discrete choice framework and an assumption of price competition, to estimate marginal costs for all producers. Using a Monte Carlo approach we generate counterfactual prices and profits for different levels of exchange rates. We illustrate the method using the market for bottled water. Our results stress that even in a relatively simple market such as this one, different brands face very different exchange rate risks.