Laussel

Publications

When do privatizations have popular support? A voting modelJournal articleRim Lahmandi-Ayed and Didier Laussel, Journal of Mathematical Economics, Volume 100, pp. 102633, 2022

We consider a general equilibrium model with vertical preferences, where workers and consumers are differentiated respectively by their sensitivity to effort and their intensity of preference for quality. We consider a public monopoly, i.e. which is owned equally by all individuals. The question is under which conditions the firm will be privatized and at which rate/price. The decisions are taken through majority vote in a plurality system. When the firm is controlled by the State, the price is determined through a vote among all the population. Otherwise, the price is the one which maximizes the profit. We prove that, when the maximum disutility of working in the firm is higher than the maximum utility of consuming its output, privatization may emerge as a possible choice of the majority, even if no hypothesis is made on the efficiency of a private management relative to a public one.

Asymmetric Information and Differentiated Durable Goods Monopoly: Intra-Period Versus Intertemporal DiscriminationJournal articleDidier Laussel, Ngo Van Long and Joana Resende, Dynamic Games and Applications, Volume 12, Issue 2, pp. 574-607, 2022

A durable good monopolist faces a continuum of heterogeneous customers who make purchase decisions by comparing present and expected price-quality offers. The monopolist designs a sequence of price-quality menus to segment the market. We consider the Markov perfect equilibrium (MPE) of a game where the monopolist is unable to commit to future price-quality menus. We obtain the novel results that: (a) under certain conditions, the monopolist covers the whole market in the first period (even when a static Mussa–Rosen monopolist would not cover the whole market), because this is a strategic means to convince customers that lower prices would not be offered in future periods and that (b) this can happen only under the stage-wise Stackelberg leadership assumption (whereby consumers base their expectations on the value of the state variable at the end of the period). Conditions under which MPE necessarily involves sequentially trading are also derived.

Dynamic monopoly and consumers profiling accuracyJournal articleDidier Laussel, Ngo Van Long and Joana Resende, Journal of Economics & Management Strategy, Volume 31, Issue 3, pp. 579-608, 2022

Using a Markov-perfect equilibrium model, we show that the use of customer data to practice intertemporal price discrimination will improve monopoly profit if and only if information precision is higher than a certain threshold level. This U-shaped relationship lends support to a popular view that knowledge is good only if it is sufficiently refined. When information accuracy can only be achieved through costly investment, we find that investing in profiling is profitable only if this allows to reach a high enough level of information precision. Consumers expected surplus being a hump-shaped function of information accuracy, we show that consumers have an incentive to lobby for privacy protection legislation which raises the cost of monopoly's investment in information accuracy. However, this cost should not dissuade firms to collect some information on customers' tastes, as the absence of consumers' profiling is actually detrimental to consumers.

Behavior based price personalization under vertical product differentiationJournal articlePaolo Garella, Didier Laussel and Joana Resende, International Journal of Industrial Organization, Volume 76, pp. 102717, 2021

We study price personalization in a two period duopoly with vertically differentiated products. In the second period, a firm not only knows the purchase history of all customers, as in standard Behavior Based Price Discrimination models, but it also collects detailed information on its old customers, using it to engage in price personalization. The analysis reveals that there exists a natural market for each firm, defined as the set of customers that cannot be poached by the rival in the second period. The equilibrium is unique, except when firms are ex-ante almost identical. In equilibrium, only the firm with the largest natural market poaches customers from the rival. This firm has highest profits but not necessarily the largest market share. Aggregate profits are lower than under uniform pricing. All consumers gain, total welfare is higher herein than under uniform pricing if firms’ natural markets are sufficiently asymmetric. The low quality firm chooses the minimal quality level and a quality differential arises, though the exact choice for the high quality depends upon the cost specification.

Is partial privatization of universities a solution for higher education? A successive monopolies modelJournal articleRim Lahmandi-Ayed, Hejer Lasram and Didier Laussel, Journal of Public Economic Theory, Volume 23, Issue 6, pp. 1174-1198, 2021

This paper accounts simply for the link between higher education and the productive economy through educated workers. We study a model of vertical successive monopolies where students/workers acquire qualification from a University then “sell” skilled labor to a monopoly which itself sells its final product to consumers, linking through quality the education sector to the labor and output markets. We determine the optimal share the State should keep in the University to compensate for the market imperfections, while taking into account the inefficiencies of public management. The resulting partially privatized University fixes the tuition fees so as to maximize a weighted sum of profits and social welfare. We derive the optimal public share under the hypothesis that the State may subsidize the tuition fees/University losses, then under the constraint that the University should make a nonnegative profit. We prove that in both cases, the State should keep a substantial share (higher under the first hypothesis) in the University, unless public management is too inefficient in which case the University's management should be completely private.

Tying the politicians’ hands: The optimal limits to representative democracyJournal articleDidier Laussel and Ngo Van Long, Journal of Public Economic Theory, Volume 22, Issue 1, pp. 25-48, 2020

The citizen candidate models of democracy assume that politicians have their own preferences that are not fully revealed at the time of elections. We study the optimal delegation problem which arises between the median voter (the writer of the constitution) and the (future) incumbent politician under the assumption that not only the state of the world but also the politician's type (preferred policy) are the policy-maker's private information. We show that it is optimal to tie the hands of the politician by imposing both a policy floor and a policy cap and delegating him/her the policy choice only in between the cap and the floor. The delegation interval is shown to be the smaller the greater is the uncertainty about the politician's type. These results are also applicable to settings outside the specific problem that our model addresses.

Marketplace or reselling? A signalling modelJournal articleNada Belhadj, Didier Laussel and Joana Resende, Information Economics and Policy, Volume 50, pp. 100834, 2020

This paper shows that the platforms’ private information on demand may explain the empirical observation that platforms like Amazon resell high-demand products, while acting as marketplace for low-demand goods. More precisely, the paper examines the strategic interaction between a seller and a better informed platform within a signalling game. We consider that the platform may choose between two distinct business models: act as a reseller or work as a pure marketplace between the buyers and the seller. The marketplace mode, which allows to internalize the spillover between the platform’s sales and the seller’s direct sales is always preferred for a low-value good. The reselling mode, which allows the platform to take advantage of its private information, may be selected in the case of high-value goods provided that (i) the externalities between direct sales and platform sales are not too strong and (ii) the difference between consumers’ willingness to pay for the high and the low-value goods is large enough. Under these conditions, the game displays a Least-Cost Separating Equilibrium in which the platform works as a marketplace for low-demand goods, while it acts as a reseller in the case of high-demand goods.

Quality and price personalization under customer recognition: A dynamic monopoly model with contrasting equilibriaJournal articleDidier Laussel, Ngo Van Long and Joana Resende, Journal of Economic Dynamics & Control, Volume 114, pp. 103869, 2020

We present a model of market hyper-segmentation, where a monopolist acquires within a short time all information about the preferences of consumers who purchase its vertically differentiated products. The firm offers a new price/quality schedule after each commitment period. Lower consumer types may have an incentive to delay their purchases until next period to obtain a better introductory offer. The monopolist counters this incentive by offering higher informational rents. Considering the dynamic game played by the monopolist and its customers, we find that there is always a Markov perfect equilibrium (MPE) in which the firm immediately sells the good to all customers, offering the Mussa-Rosen static equilibrium schedule to first time customers (and getting full commitment profits). However, if the commitment period between two offers is long enough, there is another MPE with gradual market expansion. Contrary to the Coasian result for a durable-good monopoly, we find that in both equilibria the profit of the monopolist increases (and the aggregate consumers surplus decreases) as the interval of commitment shrinks. The model yields policy implications for regulations on collection and storage of customers information. (C) 2020 Elsevier B.V. All rights reserved.

The curse of knowledge: having access to customer information can reduce monopoly profitsJournal articleDidier Laussel, Ngo Long and Joana Resende, Rand Journal of Economics, Volume 51, Issue 3, pp. 650-675, 2020

We show that a monopolist's profit is higher if he refrains from collecting coarse information on his customers, sticking to constant uniform pricing rather than recognizing customers' segments through their purchase history. In the Markov perfect equilibrium with coarse information collection, after each commitment period, a new introductory price is offered to attract new customers, creating a new market segment for price discrimination. Eventually, the whole market is covered. Shortening the commitment period results in lower profits. These results sharply differ from the ones obtained when the firm can uncover the exact willingness-to-pay of each previous customer.

Complementary Monopolies with asymmetric informationJournal articleDidier Laussel and Joana Resende, Economic Theory, Volume 70, Issue 4, pp. 943-981, 2020

We investigate how asymmetric information on final demand affects strategic interaction between a downstream monopolist and a set of upstream monopolists, who independently produce complementary inputs. We study an intrinsic private common agency game in which each supplieriindependently proposes a pricing schedule contract to the assembler, specifying the supplier's payment as a function of the assembler's purchase of inputi. We provide a necessary and sufficient equilibrium condition. A lot of equilibria satisfy this condition but there is a unique Pareto-undominated Nash equilibrium from the suppliers' point of view. In this equilibrium, there are unavoidable efficiency losses due to excessively low sales of the good. However, suppliers may be able to limit these distortions by implicitly coordinating on an equilibrium with a rigid (positive) output in bad demand circumstances.

When Is Product Personalization Profit-Enhancing? A Behavior-Based Discrimination ModelJournal articleDidier Laussel and Joana Resende, Management Science, Forthcoming

This paper investigates duopoly competition when horizontally differentiated firms are able to make personalized product-price offers to returning customers, within a behavior-based discrimination model. In the second period, firms can profile old customers according to their preferences, selling them targeted products at personalized prices. Product-price personalization (PP) allows firms to retain all old customers, eliminating second-period customer poaching. The overall profit effects of PP are shown to be ambiguous. In the second period, PP improves the matching between customers’ preferences and firms’ offers, but firms do not make any revenues in the rival’s turf. In the Bertrand outcome, second-period profits only increase for both firms if the size of their old turfs are not too different or initial products are not too differentiated. However, the additional second-period profits may be offset by lower first-period profits. PP is likely to increase firms’ overall discounted profits when consumers’ (firms’) discount factor is low (high) and firms’ initial products are exogenous and sufficiently different. When the location of initial products is endogenous, profits are hurt because of an additional location (strategic) effect aggravating head-to-head competition in the first period. Likewise, when a fraction of active consumers conceals their identity, PP increases second-period profits at the cost of aggressive first-period price competition. Finally, we show that the room for profitable PP enlarges considerably if firms rely on PP as an effective device to sustain tacit collusive outcomes, with firms credibly threatening to respond to first-period price deviations with second-period aggressive relocations of their standard products.

This paper was accepted by Matthew Shum, marketing.

Do firms always benefit from the presence of active customers?Journal articleDidier Laussel, Applied Economics, pp. 1-16, Forthcoming

We study price personalization in a two period duopoly with horizontally differentiated products. In the second period, a firm has collected detailed information on its old customers, using it to engage in price personalization. Customers, when returning to buy, may choose to incur a cost in order to access the standard offer of their previous provider in addition to its personalized offer and the standard offer of its rival. The analysis confirms that firms’ second period profits are boosted when consumers are active in this sense (being equal to perfect price discrimination ones when initial market hares do not differ too much) but it reveals that this advantage is dissipated and possibly over-dissipated by the resulting fierce first-period competition for the market. Two-period aggregate profits are smaller with active customers provided the consumers are naive and/or the firms patient enough. Consumers’ access to both personalized and standard firms’ offers which benefit the oligopolists in mature markets may plausibly hurt them in emergent ones. The equilibrium is shown not to depend on the level of the cost as long as it is below some critical value.