Business Cycles with Endogenous Mark-ups

Endogenous mark-ups have been a matter of interest in macroeconomics, especially from the middle 1990’s onwards. However, the complexity of this class of models, does not allow general ualitative conclusions in most cases, and there is plenty of room for investigation, especially in the reasons driving the emergence of multiple equilibria and non-saddle-point dynamics. In this article we extend a simple dynamic general equilibrium model to include the possibility of strategic interaction between producers in each industry, and entry affects the level of macroeconomic efficiency through an endogenous mark-up. We demonstrate multiple equilibria is a likely outcome even in an exogenous labour-supply framework. A pair of equilibria exists (a stable and an unstable one) and they are connected through a heteroclinic orbit. When we allow labour supply to vary, a third equilibrium may emerge if the government is present in the economy, and local indeterminacy may existEndogenous mark-ups, Multiple equilibria, Local dynamics

Release profile of ibuprofen in β-cyclodextrin complexes from two different solid dosage forms

The objective of this work was to develop solid dosage forms using powders containing inclusion complexes (ibuprofen with β-cyclodextrin) which were used to produce tablets (direct compression without additional excipients) and pellets (extrusion/spheronization) from wet mass containing 40% (w/w) of microcrystalline cellulose. The pellets also demonstrated that during preparation of the wet mass, the inclusion process occurred in a same yield that when pre-complexation was used. The particles characteristics were evaluated after being obtained through different complexation methods. The results showed that the tensile strength and profile dissolution were as expected for both dosage forms. Tablets containing inclusion complexes showed higher solubility when compared with a reference formulation and with two commercial formulations. The ibuprofen released from the two pellets formulations didn’t show relevant differences between them. The drug released was analyzed considering different dissolution parameters. The advantages of these new methodologies can be summarized as: (a) tablets were produced at a lower cost for the total process; and (b) in the pellet´s preparation there was no need of the previous complexation method resulting in a decrease in time and energy required

Non-Smooth Dynamics and Multiple Equilibria in a Cournt-Ramsey Model with Endogenous Markups

We consider a Ramsey model with a continuum of Cournotian industries where free entry generates an endogenous markup. The model produces two different regimes, monopoly and oligopoly, resulting in non-smooth dynamics. We analyze the global dynamics of the model, demonstrating the model may exhibit heteroclinic orbits connecting multiple equilibria. Small transitory changes in parameters can lead to large permanent effects and there can be a Rostovian poverty trap separating a low-capital and high-markup equilibrium from a high-capital low-markup equilibrium. The paper applies recent results from applied mathematics for non-smooth dynamic systems.Endogenous markups; Non-smooth dynamics; Discontinuity induced bifurcations; Heteroclinic orbits.