Search

According to its creator Michel Juillard, Dynare is a “pre-processor and a collection of routines” aimed at solving and estimating non-linear rational expectation models. This article focuses on the role of Dynare in the dissemination of dynamic stochastic general equilibrium (DSGE) models in academia and policymaking institutions. The case of Dynare highlights how the dissemination across the profession of theoretical principles and modelling practices cannot be considered independently from (at least) two general issues that involve designing computer tools for macroeconomics: tractability (i.e. the existence of a computer algorithm that can solve a mathematical problem using “reasonable” resources) and portability (i.e. the material ability of circulating and transferring a computer algorithm across models, people, and institutions). In this article, we document how the origins and the development of Dynare over three decades were guided by these two issues.

Since January 2014 this note and a manuscript entailing it have shown that the syntactic implication "Minimal linear time invariant state space representations if dynare" is false, with consequences on the vector autoregression representations of the states in the outputs. In 2020 the dynare team materially adopted the remedy of reducing its representations to minimal ones, as this note and the manuscript entailing it had been suggesting. The interested dynare user must still manually reduce the representation to minimality. [ABSTRACT FROM AUTHOR]

Integrated economic models have become popular for assessing climate change. In this paper we show how these methods can be used to assess the impact of a discard ban in a fishery. We state that a discard ban can be understood as a confiscatory tax equivalent to a value-added tax. Under this framework, we show that a discard ban improves the sustainability of the fishery in the short run and increases economic welfare in the long run. In particular, we show that consumption, capital and wages show an initial decrease just after the implementation of the discard ban then recover after some periods to reach their steady-sate values, which are 16–20% higher than the initial values, depending on the valuation of the landed discards. The discard ban also improves biological variables, increasing landings by 14% and reducing discards by 29% on the initial figures. These patterns highlight the two channels through which discard bans affect a fishery: the tax channel, which shows that the confiscation of landed discards reduces the incentive to invest in the fishery; and the productivity channel, which increases the abundance of the stock. Thus, during the first few years after the implementation of a discard ban, the negative effect from the tax channel dominates the positive effect from the productivity channel, because the stock needs time to recover. Once stock abundance improves, the productivity channel dominates the tax channel and the economic variables rise above their initial levels. Our results also show that a landed discards valorisation policy is optimal from the social welfare point of view provided that incentives to increase discards are not created. [ABSTRACT FROM AUTHOR]

The paper presents decomposition of impulse response functions (IRFs) as a new diagnostic tool for dynamic stochastic general equilibrium (DSGE) models. This method works with any DSGE model of arbitrary complexity or theoretical background. It is also applicable to any policy transmission channels. We illustrate it with monetary transmission mechanisms in two New Keynesian general equilibrium models: QUEST_III model of the European Commission and Smets-Wouters model of the USA economy. For that purpose, we use DYNARE platform for solving the models and provide a MATLAB file for IRFs decomposition. The underlying software can handle decomposition of IRFs using both the first-order and the second-order approximation of Taylor series to equilibrium relations. An IRF aggregates partial contributions of all state variables to impulse responses of a model's variable to a stochastic shock. The IRF decomposition identifies individual contributions of state variables and marks each particular channel that a policy shock uses to propagate throughout the model. We show in two illustrated cases that monetary transmission channels might be quite distinct even if DSGE models employ the same (Taylor) policy rule and reveal similar IRFs. More specifically, IRFs initiated by a monetary shock might misrepresent the pure interest rate impact on some variables. Decomposition of monetary IRFs casts more light on flexibility needed in an economy to contain negative impact of a monetary shock. [ABSTRACT FROM AUTHOR]

Macroeconomic models with sticky information include an infinite number of lagged expectations. Several authors have developed specialized solutions algorithms to solve these models under rational expectations. We demonstrate that it is also possible to implement this class of models in Dynare-a widely used software package for solving dynamic stochastic general equilibrium (DSGE) models. Using the Dynare macro language one can easily construct and change the required large number of lagged expectation terms. We assess the accuracy of simulations run with different truncation points for the lagged expectations terms and find that the solution is reasonably precise even for moderate truncation points. [ABSTRACT FROM AUTHOR]

Local (perturbation) methods compute solutions in one point and tend to deliver far lower accuracy levels than global solution methods. We develop a hybrid method that solves for some policy functions locally (using a perturbation method) and that solves for the other policy functions globally (using closed-form expressions and a numerical solver). We applied our hybrid method to solve large-scale RBC models used in the comparison analysis of Kollmann et al. (J Econ Dyn Control 35:186-202, ). We obtain more accurate solutions than those produced by any other (either local or global) solution method participating in that comparison. Our running time is a few seconds. [ABSTRACT FROM AUTHOR]