Threshold estimation for continuous three-phase polynomial regression models with constant mean in the middle regime

This paper considers a continuous three-phase polynomial regression model with two threshold points for dependent data with heteroscedasticity. We assume the model is polynomial of order zero in the middle regime, and is polynomial of higher orders elsewhere. We denote this model by ${ℳ}_2$, which includes models with one or no threshold points, denoted by ${ℳ}_1$ and ${ℳ}_0$, respectively, as special cases. We provide an ordered iterative least squares (OiLS) method when estimating ${ℳ}_2$ and establish the consistency of the OiLS estimators under mild conditions. When the underlying model is ${ℳ}_1$ and is $(d_0-1)$th-order differentiable but not $d_0$th-order differentiable at the threshold point, we further show the $O_p(N^{-1/(d_0+2)})$ convergence rate of the OiLS estimators, which can be faster than the $O_p(N^{-1/(2d_0)})$ convergence rate given in Feder when $d_0\ge 3$. We also apply a model-selection procedure for selecting ${ℳ}_{\kappa }$; $\kappa =0,1,2$. When the underlying model exists, we establish the selection consistency under the aforementioned conditions. Finally, we conduct simulation experiments to demonstrate the finite-sample performance of our asymptotic results.     

Price Discrimination in Input Markets: Downstream Entry and Efficiency

The extant theory on price discrimination in input markets takes the structure of the downstream industry as exogenously given. This paper endogenizes the structure of the downstream industry and examines the effects of permitting third‐degree price discrimination on market structure and welfare. We identify situations where permitting price discrimination leads to either higher or lower wholesale prices for all downstream firms. These findings are driven by upstream profits being discontinuous due to costly entry. Moreover, permitting price discrimination fosters entry which often improves welfare. Nevertheless, entry can also reduce welfare because it may lead to a severe inefficiency in production.     

Cost-reduction innovation under mixed economy

This paper analyzes the innovation strategies of mixed duopoly with a (semi-) public firm and a private firm, and the welfare effects of public ownership are captured. The findings indicate that the private firm is more active in research and development activities than the (semi-) public firm. Meanwhile, the total production increases with the degree of public ownership, and both firms have to suffer losses in profits. From the viewpoint of social welfare, partial nationalization is the optimal strategy. The policy implication of the findings highlights that partial nationalization should be encouraged under mixed economy.     

Employee ownership and firm performance: a meta‐analysis

Employee ownership has been an area of significant practitioner and academic interest for the past four decades. Yet, empirical results on the relationship between employee ownership and firm performance remain mixed. To aggregate findings and provide potential direction for future theoretical development, we conducted a meta‐analysis of 102 samples representing 56,984 firms. Employee ownership has a small, but positive and statistically significant relation to firm performance ( = 0.04). The effect is generally positive for studies with different sampling designs (samples assessing change in performance pre‐employee–post‐employee ownership adoption or samples on firms with employee ownership), different performance operationalisation (efficiency or growth) and firm type (publicly held or privately held). Suggesting benefits of employee ownership in a variety of contexts, we found no differences in effects on performance in publicly held versus privately held firms, stock or stock option‐based ownership plans or differences in effects across different firm sizes (i.e. number of employees). We do find that the effect of employee ownership on performance has increased in studies over time and that studies with samples from outside the USA report stronger effects than those within. We also find little to no evidence of publication bias.     

Disclosure Regulation in Duopoly Markets: Proprietary Costs and Social Welfare

Abstract

The argument of proprietary costs is commonly used by firms to object against proposed disclosure regulations. The goal of this paper is to improve our understanding of the welfare consequences of disclosure in duopoly markets and to identify market settings where proprietary costs are a viable argument for firms to remain silent. We, therefore, solve the optimal disclosure strategies and distinguish two different potentially costly effects of disclosing private information: the strategic information effect and the market information effect. We identify the market settings for which a regulator prefers to impose disclosure regulation so as to maximise consumer surplus or total surplus. Regulation may be necessary because (i) the increase in welfare outweighs proprietary costs to the firms, or (ii) firms are trapped in a prisoners' dilemma. The first primarily applies to Bertrand competition with demand uncertainty and, to a lesser extent, to Cournot competition. The second applies primarily to Cournot competition and Bertrand competition with cost uncertainty.     

A reconsideration of the link between vertical externality and managerial incentives

Previous research revealed that the strategic role of delegation contracts disappears if two quantity‐setting firms outsource input production to a monopolistic supplier. I show that this role is restored if the assumption of a downstream duopoly is relaxed. Thus, delegation contracts allow downstream profit‐maximizing owners to commit their firms to a behavior that differs from their preferences. This behavior varies nonmonotonically with the number of firms in the downstream market. Corresponding deviations from profit maximization are larger if the upstream monopolist makes a price precommitment. But little to no deviation occurs if the number of firms is large.     

Downstream Competition, Bargaining, and Welfare

I analyze the effects of downstream competition when there is bargaining between downstream firms and upstream agents (firms or unions). When bargaining is over a uniform input price, a decrease in the intensity of competition (or a merger) between downstream firms may raise consumer surplus and overall welfare. When bargaining is over a two-part tariff, a decrease in the intensity of competition reduces downstream profits and upstream utility and raises consumer surplus and overall welfare. Standard welfare results of oligopoly theory can be reversed: less competition can be unprofitable for firms and/or beneficial for consumers and society as a whole.     

Wholesale price discrimination: Innovation incentives and upstream competition

In intermediate good markets where there are alternative supply sources, wholesale price discrimination may enhance innovation incentives downstream. We consider a vertical chain where a dominant firm and a competitive fringe supply imperfect substitutes to duopoly retailers which carry both varieties. We show that a ban on price discrimination by the dominant supplier makes uniform pricing credible and reduces retailers’ incentives to decrease the cost of acquiring the competitively supplied variety, leading to higher upstream profits and lower downstream welfare. Our analysis complements existing results by identifying a novel channel through which wholesale price discrimination can improve dynamic market efficiency.     

Using Survey Sampling Algorithms For Exact Inference in Logistic Regression

Several exact inference procedures for logistic regression require the simulation of a 0-1 dependent vector according to its conditional distribution, given the sufficient statistics for some nuisance parameters. This is viewed, in this work, as a sampling problem involving a population of $n$ units, unequal selection probabilities and balancing constraints. The basis for this reformulation of exact inference is a proposition deriving the limit, as $n$ goes to infinity, of the conditional distribution of the dependent vector given the logistic regression sufficient statistics. It is proposed to sample from this distribution using the cube sampling algorithm. The interest of this approach to exact inference is illustrated by tackling new problems. First it allows to carry out exact inference with continuous covariates. It is also useful for the investigation of a partial correlation between several 0-1 vectors. This is illustrated in an example dealing with presence-absence data in ecology.     

Product Differentiation and Upstream-Downstream Relations

This paper examines the relationship between a differentiated downstream market and a specialized upstream market. We analyze three different types of vertical relation between the upstream and downstream sectors when the upstream market supplies specialized and complementary inputs to a downstream product-differentiated market. The first is the benchmark case of decentralized markets, the second is a network of alliances among upstream suppliers, and the third is partial vertical integration. We identify the perfect equilibrium for a symmetric model in each case and show that there is no simple relationship between the degree of connection between upstream and downstream firms and profitability. The key factor affecting prices and the relative profitability of the different market organizations is the degree of product differentiation among the downstream firms, because it affects the intensity of competition among upstream suppliers. We show that vertical foreclosure is not an equilibrium strategy.     

Vertical Integration and Proprietary Information Transfers

Suppose that rival downstream producers of a final good contract with the same upstream supplier of an input and, in the process, reveal private information. A vertical merger between the upstream supplier and one of the downstream firms may dissipate the information advantage of the remaining downstream firms. The welfare consequences of such a merger and related information sharing depend on the value of information, the benefits of integration apart from information sharing, and the nature of upstream competition. In this paper, conditions are found under which owners of a vertically integrated firm are better off breaking up into independent firms. This result may explain AT&T's recent spinoff of Lucent Technologies. Further results suggest that a prohibition on information transfers, such as that often proposed by the Federal Trade Commission and Department of Justice as a precursor to approving vertical mergers, may actually reduce expected consumer surplus and expected social welfare.     

Price and Quantity Contracts in a Mixed Duopoly with a Socially Concerned Firm

I study the endogenous choice of a price or quantity contract in a mixed duopoly with a socially concerned firm, which maximizes a combination of profit and consumer welfare. Equilibria with price and quantity contracts might co‐exist; welfare under price competition might be lower than under quantity competition; the firms' profit ranking might be different from that of a private duopoly or mixed duopoly with a public firm. Hence, if a firm follows a social strategy, the optimal market strategy crucially depends on the levels of social concern and competition in the market. The presence of socially concerned firms may change the mode of competition. Copyright © 2014 John Wiley & Sons, Ltd.     

Performance Measures in Dose-Finding Experiments

In the first phase of pharmaceutical development, and assuming that the probability of positive response increases with dose, the main statistical goal is to estimate a percentile of the dose–response function for a given target value $\mathrm{\Gamma }$. We compare the Maximum Likelihood and centred isotonic regression estimators of the target dose and we discuss several performance criteria to assess inferential precision, the amount of toxicity exposure and the trade-off between them for a set of some exemplary adaptive designs. We compare these designs using graphical tools. Several scenarios are considered using simulation, including the use of several start-up rules, the change of slope of the dose-toxicity function at the target dose and also different theoretical models, as logistic, normal or skew-normal distribution functions.     

Product Line Choice in Retail Duopoly

This paper develops a successive duopoly model to identify conditions under which differentiated retailers that compete in quantities, when deciding on the range of brands to offer, will carry overlapping product lines. They will do so when retail margins on each brand are not too asymmetric. Otherwise, the less profitable brand is foreclosed from the market. It is shown that welfare increases if the upstream industry is perfectly competitive, even though fewer brands may be sold. With price competition though, exclusive dealing arises when retailers are not too differentiated and in‐store competition is sufficiently intense.     

Quality of local equilibria in discrete exchange economies

This paper defines the notion of a local equilibrium of quality $(r,s)$, $0\le r,s$, in a discrete exchange economy: a partial allocation and item prices that guarantee certain stability properties parametrized by the numbers $r$ and $s$. The quality $(r,s)$ measures the fit between the allocation and the prices: the larger $r$ and $s$ the closer the fit. For $r,s\le 1$ this notion provides a graceful degradation for the conditional equilibria of Fu, Kleinberg and Lavi (2012) which are exactly the local equilibria of quality $(1,1)$. For $1<r,s$ the local equilibria of quality $(r,s)$ are more stable than conditional equilibria. Any local equilibrium of quality $(r,s)$ provides, without any assumption on the type of the agents’ valuations, an allocation whose value is at least $\frac{rs}{1+rs}$ the optimal fractional allocation. In any economy in which all agents’ valuations are $a$-submodular, i.e., exhibit complementarity bounded by $a\ge 1$, there is a local equilibrium of quality $(\frac{1}{a},\frac{1}{a})$. In such an economy any greedy allocation provides a local equilibrium of quality $(1,\frac{1}{a})$. Walrasian equilibria are not amenable to such graceful degradation.     

Market Effects of Changes in Consumers' Social Responsibility

In a duopoly model of vertical differentiation, we study market equilibrium and the resulting social welfare following an increase in the consumer's willingness to pay (WTP) for products sold by socially responsible manufacturers. Different types of such changes emerge depending on their effects on consumer heterogeneity. We show that, in most cases, increases in the consumers' social consciousness yield higher profits to socially responsible firms and may lead to higher levels of social welfare, provided that the market structure is left unchanged. However, when an increase in the consumer's social consciousness changes the market structure, welfare may fall, while the duopolists' profits rise. The resulting tension between private and social interest calls for a cautious attitude toward information campaigns aimed at increasing the consumer's social consciousness.