Study of the "mobilization" part of the national solidarity plan following the damage caused to forests by the Klaus storm of January 24, 2009.

Summary We analyzed the economic impacts of the implementation of the windfall plan after the Klaus storm in 2009 using a model representing the French forestry and wood industry (FFSM). To do so, we modified the initial model to include a representation of the storage of windfall wood and the supply of windfall wood. First, we compared a scenario without storms with a scenario with storms and without a plan and with a scenario with storms and with a plan. It appears that under the hypothesis of no degradation of wood in the forest, the plan as it was implemented favored storage compared to a situation without a plan which, on the contrary, leads to an increase in direct consumption and, to a lesser extent, export. Nevertheless, and this is the second conclusion, the plan as implemented seems to have accelerated mobilization regardless of the destination of the wood (storage, direct consumption, export). This is an important conclusion insofar as, if we assume that a part of the wood is degraded in the forest, this acceleration of mobilization avoids economic losses. For a degradation rate of 5% per year, we have seen that the plan leads to an increase in absolute value of the volume mobilized for all destinations compared to a situation without a plan. Thirdly, from the point of view of the overall surplus, the model shows that the windfall plan as implemented was beneficial since, whatever the assumption of timber degradation in the forest, the sum of the total economic surplus discounted over the period 2009-2020 is positive. Nevertheless, it appears that the value of the surplus gain calculated in relation to a scenario without the plan is very sensitive to the assumption of no wood degradation. Relaxing this assumption and taking into account a wood degradation rate of 5% leads to a fourfold increase in the overall surplus over the period 2009-2020. Fourth, the effect of the plan on upstream wood prices is limited under the non-degradation assumption. This can be explained by the relatively low values of the price elasticities of the supply functions of windfall, but also by the effect of storage in the scenario with the plan, which buffers the fall in prices but also its rise compared to a scenario without the plan. It should be noted that in an imperfect market situation, it is very likely that prices will react even less because of the effects of the capture of economic rents by one or more groups of agents. It should also be remembered that FFSM is a partial equilibrium model that does not capture the macroeconomic effects of the plan. Similarly, cyclical effects (economic crisis) are not included in the analysis. Nevertheless, FFSM models prices well above 0, whether in the scenario with or without the plan. This is a robust result to sensitivity analyses. This result means that the market does not disappear, even when no plan is implemented. We then simulated alternative scenarios to the windfall plan as it was implemented. It appears that a reallocation of part of the aid initially allocated to transport to storage would (1) limit the decline in market prices in the years following the storm, (2) increase the total surplus gain and (3) decrease the surplus gain associated with the supply of windfall. These conclusions seem relatively insensitive to the values of the elasticities of the supply of windfall with respect to costs calibrated in an ad hoc manner. On the other hand, it appears that aid at the price level, in the form of a price subsidy for upstream mobilization, leads to (1) an increase in storage and a decrease in exports and (2) an increase in the total surplus gain compared to aid at the cost level as implemented in the windfall plan. The second point of this conclusion does not seem to be very sensitive to the values of the elasticities, but the first point seems to be very sensitive to the value of these elasticities and should be considered with caution.