Economics at the Antitrust Division: 2017–2018

This article describes some of the work of Antitrust Division economists over the past year, with a focus on modeling. It begins by illustrating the mapping from evidence to prediction using tools for assessing the effects of mergers using Bertrand, Cournot, and auction models. It then turns to two hot topics in competition policy: the implications of claims of increasing margins for merger enforcement and the validity of claims of increasing concentration. Finally, it considers how mergers affect prices in bargaining models.     

Dynamic supply chain modeling using a new fuzzy hybrid negotiation mechanism

The key part of dynamic supply chain management is negotiating with suppliers and with buyers. Coordination is essential for successful supply chain management. In order to model coordination among suppliers and buyers in a dynamic supply chain, this paper takes a step further and proposes a new fuzzy- logic-based hybrid negotiation mechanism. In most real-world negotiation situations, agents have a common interest to cooperate, but have conflicting interests over exactly how to cooperate. These situations involve restrictions and preferences that may be vaguely and partly defined. Therefore, this study takes the advantage of fuzzy logic and develops a hybrid negotiation-based mechanism, that combines both cooperative and competitive negotiations. Achieving effective coordination in a multi-agent system is non-trivial as no agent possesses the global view of the problem space. Moreover, the different strategies adopted by agents may produce conflicts. While agents coordinate with each other in the operations, they will negotiate about their strategies to reduce conflicts. The proposed fuzzy hybrid negotiation mechanism allows negotiation agents more flexibility and robustness in an automated negotiation system. The proposed mechanism not only helps sellers and buyers to explore various new choices and opportunities that the e-markets offer but also allows them to identify and analyze their resource constraints in a given schedule, and helps them to explore and exploit many alternatives for a better solution. The efficacy of the proposed approach is demonstrated through an illustrative example.     

A continuous model for supply planning of assembly systems with stochastic component procurement times

This paper studies a customized product assembly scenario where some components cannot be stocked due to high component cost and risk. We consider the case where these key components are ordered after a demand has been registered with a promised delivery date. Component lead-times are stochastic and associated distribution function is known in advance. The objective is to determine the ordering time for each component such as to minimize the sum of expected holding and backlogging costs. An approach to solve this problem is proposed and the algorithm is tested on a randomly generated data set.     

Previous Marriage and the Lesbian Wage Premium

This paper provides insight into the wage gap between partnered lesbians and other groups of women. Using data from the 2000 Decennial Census, we find that wages of never-married lesbians are significantly higher than wages of previously married lesbians and other groups of women. Results indicate that controlling for previous marriage reduces the estimated lesbian wage premium by approximately 20 percent. Our research also reveals that wage patterns of previously married lesbians mirror those of cohabiting heterosexual women. Overall, our results are consistent with the notion that the lesbian wage premium is driven, in part, by differences in the labor-market commitment of lesbians and heterosexual women.     

Exploring new product portfolio management decisions: The role of managers' dispositional traits

Product strategy links to new product development (NPD) through new product portfolio management (NPPM). This dynamic decision process addresses the strategy implementation questions of identifying which new product ideas to pursue and their relative priorities. Despite the importance of NPPM in implementing product strategy, firms exhibit substantial performance-affecting differences. We investigate one potential source for such differences by examining the impact of managers' dispositional factors as a possible explanation. Using a case study research method, we examine differences in NPPM strategies and managers' revealed dispositional traits across three divisions of a single conglomerate firm operating in different business-to-business markets. Based on our analysis, we offer propositions relating managers' dispositions to NPPM strategy: analytic cognitive style is associated with balance, ambiguity tolerance is associated with strategic fit, and leadership style is associated with the relative weights applied to each dimension.     

Dynamic strategic groups: deriving spatial evolutionary paths

Recent theoretical developments in the domain of strategic groups, specifically those related to cognitive groups and strategic group identity, seem to suggest that strategic group membership is likely to be relatively stable over time and that firms in a strategic group co‐evolve. Yet appropriate data analytic approaches that use information about firms over time to identify stable strategic groups and their evolutionary paths have been lacking. To overcome such limitations, this research proposes a new clusterwise bilinear multidimensional scaling model that can simultaneously identify (1) the number of strategic groups, (2) the dimensions on which the strategic groups are based, and (3) the evolution of the strategy of these groups over time. Our discussion encompasses various alternative model specifications, together with model selection heuristics based on statistical information criteria. An illustration of the proposed methodology using data pertaining to strategic variables for a sample of public banks in the tristate area of New York, Ohio, and Pennsylvania across three time periods (1995, 1999, and 2003) identifies two underlying dimensions with five strategic groups that display very different evolutionary paths over time. Post hoc analysis shows pronounced differences in firm performance across the five derived strategic groups. This article concludes with a discussion of the implications of the findings, as well as potential future research directions. John Wiley & Sons, Ltd. Copyright © 2009 John Wiley & Sons, Ltd.     

Risk analysis for operation of aluminum heat exchangers contaminated by mercury

Brazed aluminum plate-fin heat exchangers are extensively used in gas separation processes including LNG, LPG, NGL, nitrogen rejection and olefins manufacture. In situations where mercury is a trace component of feed gas or liquid feeds to crackers, condensation of liquid or precipitation of solid mercury can occur in heat exchanger passes, even with functional mercury removal systems in place. Mercury in liquid phase causes, under certain well-defined conditions, liquid metal embrittlement of susceptible metallurgy or amalgam corrosion of core fins, both of which can lead to sudden loss of pressure containment. Mercury-contaminated aluminum heat exchangers require close scrutiny and quantitative risk assessment to allow safe operation, remediation or to justify replacement. The risk analysis procedure involves computational prediction of mercury deposition, inspection of critical areas, detailed assessment of metallurgy and fabrication, strain analysis of temperature changes during trips and shutdowns and oxide fatigue analysis. Assigning probability of equipment failure requires a complete understanding of the mechanisms of liquid metal embrittlement and amalgam corrosion that operate on aluminum plate-fin heat exchangers. Statistical correlations to known failures are essential to assignment of probability-based risk factors. Probabilities of leak and rupture failure modes can be estimated using amounts and locations of mercury deposits determined from focused inspection or calculated thermodynamically. © 2009 American Institute of Chemical Engineers Process Saf Prog, 2009     

The Impact of Deregulation and Financial Innovation on Consumers: The Case of the Mortgage Market

We develop a technique to assess the impact of changes in mortgage markets on households, exploiting an implication of the permanent income hypothesis: The higher a household's expected future income, the higher its desired consumption, ceteris paribus. With perfect credit markets, desired consumption matches actual consumption and current spending forecasts future income. Because credit market imperfections mute this effect, the extent to which house spending predicts future income measures the "imperfectness" of mortgage markets. Using micro-data, we find that since the early 1980s, mortgage markets have become less imperfect in this sense, and securitization has played an important role.     

Pricing catastrophe options with stochastic claim arrival intensity in claim time

We model claim arrival and loss uncertainties jointly in a doubly-binomial framework to price an Asian-style catastrophe (CAT) option with a non-traded underlying loss index using the no-arbitrage martingale pricing methodology. We span these uncertainties by benchmarking to the shadow price of a one-claim bond and the premium of a reinsurance contract. We implement a stochastic time change from calendar time to claim time to more efficiently price the CAT option as a random sum – a binomial sum of claim time binomial Asian option prices. This choice of the operational time dimension allows us to incorporate different patterns of catastrophe arrivals by adjusting the claim arrival probability. We demonstrate this versatility by incorporating a mean-reverting Ornstein-Uhlenbeck intensity arrival process. Simulation results verify our model predictions and demonstrate how the claim arrival probability varies with the expected claim arrival intensity.