Hyperbolicity, transitivity and the two-sided limit shadowing property

We explore the notion of two-sided limit shadowing property introduced by Pilyugin \cite{P1}. Indeed, we characterize the $C^1$-interior of the set of diffeomorphisms with such a property on closed manifolds as the set of transitive Anosov diffeomorphisms. As a consequence we obtain that all codimention-one Anosov diffeomorphisms have the two-sided limit shadowing property. We also prove that every diffeomorphism $f$ with such a property on a closed manifold has neither sinks nor sources and is transitive Anosov (in the Axiom A case). In particular, no Morse-Smale diffeomorphism have the two-sided limit shadowing property. Finally, we prove that $C^1$-generic diffeomorphisms on closed manifolds with the two-sided limit shadowing property are transitive Anosov. All these results allow us to reduce the well-known conjecture about the transitivity of Anosov diffeomorphisms on closed manifolds to prove that the set of diffeomorphisms with the two-sided limit shadowing property coincides with the set of Anosov diffeomorphisms.Comment: 10 page

N-expansive homeomorphisms with the shadowing property

We discuss the dynamics of $n$-expansive homeomorphisms with the shadowing property defined on compact metric spaces. For every $n\in\mathbb{N}$, we exhibit an $n$-expansive homeomorphism, which is not $(n-1)$-expansive, has the shadowing property and admits an infinite number of chain-recurrent classes. We discuss some properties of the local stable (unstable) sets of $n$-expansive homeomorphisms with the shadowing property and use them to prove that some types of the limit shadowing property are present. This deals some direction to the problem of non-existence of topologically mixing $n$-expansive homeomorphisms that are not expansive

On homeomorphisms with the two-sided limit shadowing property

We prove that the two-sided limit shadowing property is among the strongest known notions of pseudo-orbit tracing. It implies shadowing, average shadowing, asymptotic average shadowing and specification properties. We also introduce a weaker notion that is called two-sided limit shadowing with a gap and prove that it implies shadowing and transitivity. We show that those two properties allow to characterize topological transitivity and mixing in a class of expansive homeomorphisms and hence they characterize transitive (mixing) shifts of finite type.Comment: 1 figure, comments are welcome

Food Security, Food Chains and Bioenergy Challenges for a Sustainable Development Environment

Food system dynamics worldwide are under a new paradigm. Energy supply based on renewable natural resources is now a necessary solution, where agri-business can play an important role, and food systems will have to interact worldwide with new competitors for land and agriculture activity. The argument in this paper is based on the evidence that innovation and technology changes in food production (agricultural production) can offer a sustainable supply of grain and biomass, when demand behaviour is consistent and very flexible (demand elasticity above 1). The main argument is based on the hypothesis that demand behaviour is the main driver in food systems, which can be observed looking at technical and technological changes in production systems in Europe and elsewhere, such as Latin America, and more specifically Brazil. Economic surplus distribution across the food chain is another key factor for the induced innovation process to occur dynamically in food and agricultural production, based on well functioning markets such as the international markets (elastic demand for most countries). Science will face a new industry demand for solutions on the production side that are able to provide sustainability and supply increases that have to support empowerment of the primary sector to help producers capture surplus created by new technology possibilities, and “new demands”. Technological changes will occur quickly enough to avoid strong changes in prices if, and only if, producers are able to look at new opportunities with conditions (and sufficient time) to improve their business (and share on economic surplus). Institutional innovation is another key factor in the food system, and should also provide capability to create value to a set of intangible goods provided by the primary sector, giving space for a multi-functionality perspective on the primary sector activity, such as environment and sustainability considerations. The first factor to be considered is certainly the market functioning, because food production traditionally suffers from market problems, which began with the characteristics of the products, space diversity, conservation problems, and production seasonality (to mention only the most obvious). Other considerations related with the environment, and non tangible goods, such as the landscape dimension (and other dimensions on man’s relationship with nature), will continue to deserve new initiatives to improve the Quality of Life.Agribusiness, Agricultural and Food Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Industrial Organization,

Ineffective Controls on Capital Inflows Under Sophisticated Financial Markets: Brazil in the Nineties

We analyze the Brazilian experience in the 1990s to assess the effectiveness of controls on capital inflows in restricting financial inflows and changing their composition towards long term flows. Econometric exercises (VARs) showed that controls on capital inflows were effective in deterring financial inflows for only a brief period, from two to six months. The hypothesis to explain the ineffectiveness of the controls is that financial institutions performed several operations aimed at avoiding capital controls. To check this hypothesis, we conducted interviews with market players. We collected several examples of the financial strategies engineered to avoid the capital controls and invest in the Brazilian fixed income market. The main conclusion is that controls on capital inflows, while they may be desirable, are of very limited effectiveness under sophisticated financial markets.

State-controlled companies and political risk: evidence from the 2014 Brazilian election

This paper examines the vulnerability of state-controlled companies to political risk using the 2014 Brazilian election and data on stock options. In her first term as Brazilian president, Ms. Dilma Rousseff took measures that were not aligned with the objective of maximizing profits of Petrobras, the Brazilian state-controlled oil company. She was reelected president in 2014. Results show that Petrobras would be worth around 62% (USD 45 billion) more if the opposition candidate had won the election. Using our estimated reelection probabilities and stock price data, we also find that the election of Ms. Rousseff had a negative impact on the value of several companies, but the effects on Petrobras and Banco do Brasil, the state-controlled bank, were particularly strong