The Comparison of ad Valorem and Specific Taxation under Uncertainty

The comparison between specific (per unit) and ad valorem (percentage) taxation has been one of the oldest issues in public finance. In Cournot markets, with deterministic costs structures, conventional wisdom has it that ad valorem taxation tax‐revenue dominates specific. It is shown that in the presence of uncertainty, regarding firms’ cost structures, and under reasonable conditions, the conventional wisdom might not hold. The implication of this, from a policy perspective, is that the precise evaluation of the two types of taxation requires an explicit consideration of cost uncertainty.     

Progressive taxation and macroeconomic stability in two-sector models with social constant returns

It has been shown that, in the two-sector Benhabib–Farmer–Guo model with technologies of social increasing returns that exhibits indeterminacy, progressive income taxes de-stabilize the economy. This paper revisits the robustness of the tax implication in the two-sector Benhabib–Nishimura model with technologies of social constant returns that exhibits indeterminacy. We show that a progressive income tax stabilizes the economy against sunspot fluctuations, and thus the tax implication based on the two-sector Benhabib–Farmer–Guo model is not robust.     

Product differentiation,price discrimination and collusion

The existing literature which analyses the relationship between the product differentiation degree and the sustainability of a collusive agreement on price assumes that firms cannot price discriminate, and concludes that there is a negative relationship between the product differentiation degree and the critical discount factor. This paper, in contrast, assumes that firms are able to price discriminate. Within the Hotelling framework, three different collusive schemes are studied: perfect collusion on discriminatory prices; perfect collusion on a uniform price; collusion not to discriminate. We obtain that the critical discount factor of the first and the third collusive scheme does not depend on the product differentiation degree, while the critical discount factor of the second collusive scheme depends positively on the product differentiation degree. Moreover, we show that imperfect collusion is more difficult to sustain than perfect collusion.     

Some Taxation Theorems in the Hotelling Model

In this paper, we investigate the relationship between the demand ad valorem, cost ad valorem and unit taxes in terms of price, quantity and tax revenue. In particular, we prove that the Musgravian transformation holds in the Hotelling model. In addition, we show that the Suits‐Musgrave theorem must be revised as output in the Hotelling model remains invariant in the presence of different taxes. That is, for a given price instead of a given output, the tax revenue under demand ad valorem tax exceeds that under the corresponding unit tax as long as profit levels for both stores are positive, a very general assumption. The exception is when the two stores are located close to each other and transportation cost is zero. Only in this case, are tax revenues and price under both tax regimes the same. If both stores are symmetrically located, the superiority of the ad valorem tax holds true except when the two stores are located back to back. Finally the farther away the location of a firm from the end point is, the smaller the difference in tax revenues between demand ad valorem and unit tax will be: the effect of the Suits‐Musgrave theorem weakens in the presence of location clustering.     

Unit versus Ad Valorem Taxes in Multiproduct Cournot Oligopoly

The welfare dominance of ad valorem taxes over unit taxes in a single‐market Cournot oligopoly is well known. This article extends the analysis to multimarket oligopoly. Provided all ad valorem taxes are equal and positive, unit costs are constant, firms are active in all considered markets, and a representative consumer has convex preferences, ad valorem taxes are shown to dominate in multiproduct equilibrium. Conditions exist, however, under which economic efficiency declines upon replacing specific taxes with ad valorem taxes that preserve output levels. We discuss the roles of unit cost covariances across multiproduct firms, and also of complementarity in demand, in determining the extent of cost efficiencies arising under ad valorem taxation. For goods that are complementary or independent in demand, conditions are found such that industry profits decline upon use of ad valorem taxes.     

Algebra of Integrated Time Series: Evidence from Unit Root Analysis

It is argued if x_t ~ I(1) and y_t ~ I(1), then running a regression x_t on y_t would produce spurious results because e _t would generally be I(1). However, there may exist a ‘b’ such that e _t  = x _t - by _t is I(0), then running a regression x _t on y _t would not produce spurious results. This special case of two integrated time series is known in the literature as cointegration. In this particular case, x _t and y _t are said to be cointegrated. In our review of the development of the concept of cointegration, we identified that the underlying reason for this special case to arise is the proposition that if x _t  ~ I(d _x ), y _t  ~ I(d _y ), then z _t  = bx _t  + cy _t  ~ I(max(d _x ,d _y )). In this research, we offer evidence against this proposition.     

Cartel sustainability with vertical product differentiation: Price versus quantity competition

In the context of a vertically differentiated duopoly, we analyse the influence of the degree of differentiation on cartel sustainability, under both price and quantity competition. We find that, under both Bertrand and Cournot competition, the effect of vertical product differentiation on sustainability of the collusive equilibrium is unclear. It is shown that, given a degree of differentiation, price collusion is more sustainable than quantity collusion.     

Declining Discount Rates: The Long and the Short of it

The last few years have witnessed important advances in our understanding of time preference and social discounting. In particular, several rationales for the use of time-varying social discount rates have emerged. These rationales range from the ad hoc to the formal, with some founded solely in economic theory while others reflect principles of intergenerational equity. While these advances are to be applauded, the practitioner is left with a confusing array of rationales and the sense that almost any discount rate can be justified. This paper draws together these different strands and provides a critical review of past and present contributions to this literature. In addition to this we highlight some of the problems with employing DDRs in the decision-making process, the most pressing of which may be time inconsistency. We clarify their practical implications, and potential pitfalls, of the more credible rationales and argue that some approaches popular in environmental economics literature are ill-conceived. Finally, we illustrate the impact of different approaches by examining global warming and nuclear power investment. This includes an application and extension of Newell and Pizer [‘Discounting the benefits of climate change mitigation : how much do uncertain rates increase valuations?’ Journal of Environmental Economics and Management 46 (2003) 52] to UK interest rate data.     

On choosing which game to play when ignorant of the rules

This paper suggests a theory of choice among strategic situations when the rules of play are not properly specified. We take the view that a “strategic situation” is adequately described by a TU game since it specifies what is feasible for each coalition but is silent on the procedures that are used to allocate the surplus. We model the choice problem facing a decision maker (DM) as having to choose from finitely many “actions”. The known “consequence” of the ith action is a coalition from game f _i over a fixed set of players \(N_i\cup\{d\}\) (where d stands for the DM). Axioms are imposed on her choice as the list of consequences (f ₁,..., f _m ) from the m actions varies. We characterize choice rules that are based on marginal contributions of the DM in general and on the Shapley Value in particular.     

Cartel size and collusive stability with non-capitalistic players

A well established belief both in the game-theoretic IO and in policy debates is that market concentration facilitates collusion. We show that this piece of conventional wisdom relies upon the assumption of profit-seeking behaviour, for it may be reversed when firms pursue other plausible goals. To illustrate our intuition, we investigate the incentives to tacit collusion in an industry formed by labour-managed (LM$LM$) enterprises. We characterise the perfect equilibrium of a supergame in which LM$LM$ firms play an infinitely repeated Cournot game under grim trigger strategies. We show that the critical threshold of the discount factor above which collusion is stable (i) is lower in the LM$LM$ industry than in the capitalistic one; (ii) monotonically decreases with the number of firms.     

Vertical integration, raising rivals’ costs and upstream collusion

This paper analyzes the impact vertical integration has on upstream collusion when the price of the input is linear. As a first step, the paper derives the collusive equilibrium that requires the lowest discount factor in the infinitely repeated game when one firm is vertically integrated. It turns out this is the joint-profit maximum of the colluding firms. The discount factor needed to sustain this equilibrium is then shown to be unambiguously lower than the one needed for collusion in the separated industry. While the previous literature has found it difficult to reconcile raising-rivals’-costs strategies following a vertical merger with equilibrium behavior in the static game, they are subgame perfect in the repeated game studied here.     

Tops-only domains

In this paper we consider the standard voting model with a finite set of alternatives A and n voters and address the following question: what are the characteristics of domains \({\mathcal D}\) that induce the property that every strategy-proof social choice function \({f: {\mathcal D}^n \rightarrow A}\) satisfying unanimity, has the tops-only property? We first impose a minimal richness condition which ensures that for every alternative a, there exists an admissible ordering where a is maximal. We identify conditions on \({\mathcal D}\) that are sufficient for strategy-proofness and unanimity to imply tops onlyness in the general case of n voters and in the special case, n = 2. We provide an algorithm for constructing tops-only domains from connected graphs with elements of A as nodes. We provide several applications of our results. Finally, we relax the minimal richness assumption and partially extend our results.     

Persistency of Turkish export shocks: a quantile autoregression (QAR) approach

This study analyzes the persistency of total and disaggregated Turkish exports for different shock magnitudes using the quantile autoregression (QAR) method in line with Koenker and Xiao (J Am Stat Assoc 99:775–787, 2004). The results suggest that the persistence of shocks are not similar across different quantiles of Total Exports and disaggregated export sectors, indicating an asymmetry in the case of negative and positive shocks across different export sectors. The persistency behavior of Total Exports as well as Food and Beverages, Chemicals, Basic Metals, Raw Materials, Motor Vehicles and Radio & TV exports are asymmetric to negative versus positive shocks, which cannot be captured by traditional unit root tests. Thus, sound interpretation of QAR results is necessary for policy makers to identify shock characteristics and thereby pursue appropriate policies for overcoming adverse impacts on the economy.     

Human agency and convergence: Gaus’s Kantian Parliamentarian

Public reason is justified to the extent that it uses (only) arguments, assumptions, or goals that are allowable as “public” reasons. But this exclusion requires some prior agreement on domains, and a process that disallows new unacceptable reasons by unanimous consent. Surprisingly, this problem of reconciliation is nearly the same, mutatis mutandis, as that faced by micro-economists working on general equilibrium, where a conceit—tâtonnement, directed by an auctioneer—was proposed by Leon Walras. Gaus’s justification of public reason requires the “as if” solution of a Kantian Parliamentarian, who rules on whether a proposal is “in order.” Previous work on public reason, by Rousseau, Kant, and Rawls, have all reduced decision-making and the process of “reasoning” to choice by a unitary actor, thereby begging the questions of disagreement, social choice, and reconciliation. Gaus, to his credit, solves that problem, but at the price of requiring that the process “knows” information that is in fact indiscernible to any of the participants. In fact, given the dispersed and radical situatedness of human aims and information, it is difficult for individuals, much less groups, to determine when norms are publicly justified or not. More work is required to fully take on Hayek’s insight that no person, much less all people, can have sufficient reasons to endorse the relevant norm, rule or law.     

Mixture periodic GARCH models: theory and applications

This paper discusses mixture periodic GARCH (M-PGARCH) models that constitute very flexible class of nonlinear time series models of the conditional variance. It turns out that they are more parsimonious comparatively to MPARCH models. We first provide some probabilistic properties of this class of models. We thus propose an estimation method based on the expectation-maximization algorithm. Finally, we apply this methodology to model the spot rates of the Algerian dinar against euro and US dollar. This empirical analysis shows that M-PGARCH models yield the best performance among the competing models.     

Cartel Stability and Economic Integration

This paper revisits the notion that economic integration—modeled as a reduction of trade costs—may be anticompetitive, in the sense that it may reinforce the ability of an international cartel to maintain a collusive understanding about staying out of each other’s markets. The paper is novel in terms of introducing ad valorem and fixed trade costs in addition to the customary unit trade costs. It is shown that an anticompetitive effect, found for reductions in unit trade costs, may disappear once trade costs are ad valorem or fixed.     

The prosumers and the grid

Prosumers are households that are both producers and consumers of electricity. A prosumer has a grid-connected decentralized production unit and makes two types of exchanges with the grid: energy imports when the local production is insufficient to match the local consumption and energy exports when local production exceeds it. There exists two systems to measure the exchanges: a net metering system that uses a single meter to measure the balance between exports and imports and a net purchasing system that uses two meters to measure separately power exports and imports. Both systems are currently used for residential consumption. We build a model to compare the two metering systems. Under net metering, the price of exports paid to prosumers is implicitly set at the price of the electricity that they import. We show that net metering leads to (1) too many prosumers, (2) a decrease in the bills of prosumers, compensated via a higher bill for traditional consumers, and (3) a lack of incentives to synchronize local production and consumption.     

Joint misrepresentation with bribes

We study the problem of assigning objects to buyers. Monetary transfers are allowed. Each buyer’s preference space contains, but is not limited to, the linear additively separable preferences. A rule maps each preference profile to an allocation. We are concerned about the possibility that a group of buyers may engage in the following kind of manipulation: They make side payments internally and then carry out a joint misrepresentation. A rule is strongly group strategy-proof if no group can gain by engaging in such operations. We also consider several other appealing requirements. We find that the posted-price rules are the only one that satisfies non-triviality, non-imposition, envy-freeness, and strong group strategy-proofness.     

On the Equivalence of Ad Valorem Tariffs and Specific Tariffs under Duopoly*

Using a quantity conjectural variation model, this paper examines whether an ad valorem tariff and a specific tariff are equivalent under duopoly. We show that if the average per‐unit import tax is the same for the two tariffs, domestic output will be smaller while foreign output will be larger under an ad valorem tariff. We further show that for any value of a specific tariff, there is a Pareto‐superior ad valorem tariff for all values of conjectural variation except in the case of perfect competition where the two tariffs are equivalent.     

Rock around the clock: An agent-based model of low- and high-frequency trading

We build an agent-based model to study how the interplay between low- and high-frequency trading affects asset price dynamics. Our main goal is to investigate whether high-frequency trading exacerbates market volatility and generates flash crashes. In the model, low-frequency agents adopt trading rules based on chronological time and can switch between fundamentalist and chartist strategies. By contrast, high-frequency traders activation is event-driven and depends on price fluctuations. High-frequency traders use directional strategies to exploit market information produced by low-frequency traders. Monte-Carlo simulations reveal that the model replicates the main stylized facts of financial markets. Furthermore, we find that the presence of high-frequency traders increases market volatility and plays a fundamental role in the generation of flash crashes. The emergence of flash crashes is explained by two salient characteristics of high-frequency traders, i.e., their ability to i. generate high bid-ask spreads and ii. synchronize on the sell side of the limit order book. Finally, we find that higher rates of order cancellation by high-frequency traders increase the incidence of flash crashes but reduce their duration.