Innovation under taxes versus permits : how a commonly made assumption leads to misleading recommendations

The literature on the impact of economic instruments (typically taxes and tradable permits) on the level of innovation is usually based on the assumption that innovation reduces the slope of the marginal abatement cost curve. This assumption, which usually leads to the conclusion that taxes induce higher levels of innovation than tradable permits, is however never motivated. In this short article, we analyse the assumption by introducing innovation in the production function as a polluting firm and by showing how it affects the corresponding marginal abatement cost curve. We show that the slope of the marginal abatement cost curvedoes not necessarily decrease with the level of innovation. As a consequence, previous analyses lead to misleading policy recommendations

Environmental policy and speculation on markets for emission permits

Tradable emission permits share many characteristics with financial assets. As on financial markets, speculators are likely to be active on large markets for emission permits such as those developing under the Kyoto Protocol. We show how the presence of speculators on a market for emission permits affects the price of these permits when firms face risk aversion. The agency in charge of the optimal environmental policy should account for the presence of speculators when determining the total amount of permits to issue.

Should developing countries participate in the Clean Development Mechanism under the Kyoto Protocol ? The low-hanging fruits and baseline issues

Under the Kyoto Protocol, industrialized countries committed to emission reductions may fullfil part of their obligations by implementing emission reduction projects in developing countries. In doing so, they make use of the so-called Clean Development Mechansim (CDM). Two important issues surround the implementation of the CDM. First, if the cheapest abatment measures are implemented for CDM projects, developing countries may be left with only more expensive measures when they have to meet their own commitments in the future (the so-called low-hanging fruits issue). Second, a choice must be made on the type of baseline against which emission reductions are measured : an absolute baseline or a relative (to output) one (the baseline issue). The purpose of this paper is to study the interactions between these two issues from the point of view of the developing country. Two major results are obtained. First, when possible future commitments for developing countries and irreversibility of abatement measures are taken into account, we show that the industry where CDM projects are implemented enjoys large profits under an absolute baseline than under a relative one. Second, concerning the low-hanging fruits problem, the financial compensation required by the developing country for implementing ‘too many’ CDM projects is larger under the relative baseline.

Deformed graphical zonotopes

We study deformations of graphical zonotopes. Deformations of the classical permutahedron (which is the graphical zonotope of the complete graph) have been intensively studied in recent years under the name of generalized permutahedra. We provide an irredundant description of the deformation cone of the graphical zonotope associated to a graph $G$, consisting of independent equations defining its linear span (in terms of non-cliques of $G$) and of the inequalities defining its facets (in terms of common neighbors of neighbors in $G$). In particular, we deduce that the faces of the standard simplex corresponding to induced cliques in $G$ form a linear basis of the deformation cone, and that the deformation cone is simplicial if and only if $G$ is triangle-free.Comment: 13 pages, 3 figures. Version 2: Added figures, improved presentatio

Deformed Graphical Zonotopes

We study deformations of graphical zonotopes. Deformations of the classical permutahedron (which is the graphical zonotope of the complete graph) have been intensively studied in recent years under the name of generalized permutahedra. We provide an irredundant description of the deformation cone of the graphical zonotope associated to a graph $G$, consisting of independent equations defining its linear span (in terms of non-cliques of $G$ ) and of the inequalities defining its facets (in terms of common neighbors of neighbors in $G$ ). In particular, we deduce that the faces of the standard simplex corresponding to induced cliques in $G$ form a linear basis of the deformation cone, and that the deformation cone is simplicial if and only if $G$ is triangle-free

Contribution à la Caractérisation des Sédiments Superficiels Quaternaires de la Partie Sud du Marais Poitevin (Poitou-Charentes-France)

Le système hydrogéologique de la partie sud du marais Poitevin est très peu connu. Cette étude vise à définir les caractéristiques sédimentologiques ou physiques des sédiments du quaternaire en vue d’acquérir des connaissances sur le système hydrogéologique pour une gestion durable. Pour cela, la cartographie par krigeage de l’épaisseur des formations quaternaires, la granulométrie laser et la description minéralogique par diffractomètre des rayons X ont été utilisées. En général, les épaisseurs des formations quaternaires varient de 0 à plus de 20 m avec des épaisseurs plus importantes au Nord et au Nord-Ouest de la zone d’étude. Ces épaisseurs varient de façon spécifique de 20 à 54 m au niveau de Saint Hilaire la Palud. En se déplaçant de l’Ouest vers l'Est, la granulométrie est plus grossière au Sud et plus fine au Nord contrairement à la bordure Est où, cette tendance est inversée. Les faciès rencontrés sont des limons généralement plus fins en surface qu’en profondeur avec ou sans présence de coquillages, passant latéralement à des sables ou à des débris calcaires. Les sédiments de surface ont une faible perméabilité (de 10-7 à 10-6 m.s-1) par rapport à ceux rencontrés en profondeur avec, des valeurs de perméabilité pouvant atteindre 10-4 m.s-1. Cette perméabilité est plus élevée sur la bordure sud que sur la bordure nord de la zone d'étude. Le cortège minéralogique est dominé par les minéraux quartzo-feldspathiques en surface, et de fortes variations des teneurs en minéraux carbonatés en profondeur. Les formations quaternaires mettent en évidence la "nappe du Bri" (en surface) et des "pseudo-nappes" (en profondeur), identifiées comme étant moins productives au plan hydrogéologique. L'ensemble de ces formations quaternaires repose sur le substratum carbonaté Jurassique.   The hydrogeological system of the southern part of the Poitevin marsh is very little known. This study aims to define the sedimentological or physical characteristics of Quaternary sediments in order to acquire knowledge on the hydrogeological system for sustainable management. for this, kriging mapping of the thickness of the quaternary formations, laser granulometry and mineralogical description by X-ray diffractometer were used. In general, the thicknesses of the quaternary formations vary from 0 to more than 20 m with greater thicknesses in the North and North-West of the study area. These thicknesses vary specifically from 20 to 54 m at Saint Hilaire la Palud. Moving from west to east, the grain size is coarser in the south and finer in the north, unlike the eastern border where this trend is reversed. The facies encountered are silts generally finer at the surface than at depth with or without the presence of shells, passing laterally to sand or limestone debris. Surface sediments have a low permeability (from 10-7 to 10-6 m.s-1) compared to those found at depth with permeability values that can reach 10-4 m.s-1. This permeability is higher on the southern edge than on the northern edge of the study area. The mineralogical procession is dominated by quartzo-feldspathic minerals at the surface, and strong variations in the contents of carbonate minerals at depth. The Quaternary formations highlight the "Bri aquifer" (on the surface) and "pseudo-aquifers" (at depth), identified as being less productive from a hydrogeological point of view. All of these quaternary formations rest on the Jurassic carbonated substratum

Contribution à la Caractérisation des Sédiments Superficiels Quaternaires de la Partie Sud du Marais Poitevin (Poitou-Charentes-France)

Le système hydrogéologique de la partie sud du marais Poitevin est très peu connu. Cette étude vise à définir les caractéristiques sédimentologiques ou physiques des sédiments du quaternaire en vue d’acquérir des connaissances sur le système hydrogéologique pour une gestion durable. Pour cela, la cartographie par krigeage de l’épaisseur des formations quaternaires, la granulométrie laser et la description minéralogique par diffractomètre des rayons X ont été utilisées. En général, les épaisseurs des formations quaternaires varient de 0 à plus de 20 m avec des épaisseurs plus importantes au Nord et au Nord-Ouest de la zone d’étude. Ces épaisseurs varient de façon spécifique de 20 à 54 m au niveau de Saint Hilaire la Palud. En se déplaçant de l’Ouest vers l'Est, la granulométrie est plus grossière au Sud et plus fine au Nord contrairement à la bordure Est où, cette tendance est inversée. Les faciès rencontrés sont des limons généralement plus fins en surface qu’en profondeur avec ou sans présence de coquillages, passant latéralement à des sables ou à des débris calcaires. Les sédiments de surface ont une faible perméabilité (de 10-7 à 10-6 m.s-1) par rapport à ceux rencontrés en profondeur avec, des valeurs de perméabilité pouvant atteindre 10-4 m.s-1. Cette perméabilité est plus élevée sur la bordure sud que sur la bordure nord de la zone d'étude. Le cortège minéralogique est dominé par les minéraux quartzo-feldspathiques en surface, et de fortes variations des teneurs en minéraux carbonatés en profondeur. Les formations quaternaires mettent en évidence la "nappe du Bri" (en surface) et des "pseudo-nappes" (en profondeur), identifiées comme étant moins productives au plan hydrogéologique. L'ensemble de ces formations quaternaires repose sur le substratum carbonaté Jurassique.   The hydrogeological system of the southern part of the Poitevin marsh is very little known. This study aims to define the sedimentological or physical characteristics of Quaternary sediments in order to acquire knowledge on the hydrogeological system for sustainable management. for this, kriging mapping of the thickness of the quaternary formations, laser granulometry and mineralogical description by X-ray diffractometer were used. In general, the thicknesses of the quaternary formations vary from 0 to more than 20 m with greater thicknesses in the North and North-West of the study area. These thicknesses vary specifically from 20 to 54 m at Saint Hilaire la Palud. Moving from west to east, the grain size is coarser in the south and finer in the north, unlike the eastern border where this trend is reversed. The facies encountered are silts generally finer at the surface than at depth with or without the presence of shells, passing laterally to sand or limestone debris. Surface sediments have a low permeability (from 10-7 to 10-6 m.s-1) compared to those found at depth with permeability values that can reach 10-4 m.s-1. This permeability is higher on the southern edge than on the northern edge of the study area. The mineralogical procession is dominated by quartzo-feldspathic minerals at the surface, and strong variations in the contents of carbonate minerals at depth. The Quaternary formations highlight the "Bri aquifer" (on the surface) and "pseudo-aquifers" (at depth), identified as being less productive from a hydrogeological point of view. All of these quaternary formations rest on the Jurassic carbonated substratum