The Adequacy of the Traditional Econometric Approach to Nonlinear Cycles

To show that the traditional econometric approach is not able to deal with deterministic chaos, we use an extension of Goodwin.s growth cycle model to generate arti.cial data for output. An EGARCH model is estimated to describe the data generation process. Although using some traditional econometric tests no evidence of misspeci.- cation is found the estimated process is qualitatively wrong: it is dynamically stable when the true process is unstable. We present a speci.c econometric procedure de- veloped to deal with deterministic chaos: the BDS statistics. Also an explanation for the little evidence of deterministic chaos in aggregated macroeconomic time series is suggested.

The Stability Properties of Goodwin's Growth Cycle Model

It is known that Goodwin.s Predator-Prey model suffers from structural instability. In its pure form the model has a neutral equilibrium. Ploeg (1985) showed that if the hypothesis of fixed proportions technology was relaxed then the equilibrium would become stable. We show here that the equilibrium becomes unstable when some sort of endogenous cyclical labour productivity is considered. Then we will study the consequences of considering both effects concluding that the stabilizing effect of considering a flexible technology is much stronger than the destabilizing effect of endogenizing labour productivity.

Public vs Private Schooling in an Endogenous Growth Model

I present an overlapping generations model, with formal education as the engine of growth, close to Glomm and RaviKumar (1992). Contrary to Glomm and Ravikumar, I Show that public schooling, when compared to a private system, may stimulate economic growth.

FastM: Design and Evaluation of a Fast Mobility Mechanism for Wireless Mesh Networks

Although there is a large volume of work in the literature in terms of mobility approaches for Wireless Mesh Networks, usually these approaches introduce high latency in the handover process and do not support realtime services and applications. Moreover, mobility is decoupled from routing, which leads to inefficiency to both mobility and routing approaches with respect to mobility. In this paper we present a new extension to proactive routing protocols using a fast mobility extension, FastM, with the purpose of increasing handover performance in Wireless Mesh Networks. With this new extension, a new concept is created to integrate information between neighbor wireless mesh routers, managing locations of clients associated to wireless mesh routers in a certain neighborhood, and avoiding packet loss during handover. The proposed mobility approach is able to optimize the handover process without imposing any modifications to the current IEE 802.11 MAC protocol and use unmodified clients. Results show the improved efficiency of the proposed scheme: metrics such as disconnection time, throughput, packet loss and control overhead are largely improved when compared to previous approaches. Moreover, these conclusions apply to mobility scenarios, although mobility decreases the performance of the handover approach, as expected

A note on oil dependence and economic instability

We show that dependence on foreign energy can increase economic instability by raising the likelihood of equilibrium indeterminacy, hence making fluctuations driven by self-fulfilling expectations easier to occur. This is demonstrated in a standard neoclassical growth model. Calibration exercises, based on the estimated share of imported energy in production for several countries, show that the degree of reliance on foreign energy for many countries can easily make an otherwise determinate and stable economy indeterminate and unstable.Petroleum industry and trade ; Economic stabilization

OPEC´s Oil Exporting Strategy and Macroeconomic (In)Stability

Aguiar-Conraria and Wen (2008) argued that dependence on foreign oil raises the likelihood of equilibrium indeterminacy (economic instability) for oil importing countries. We argue that this relation is more subtle. The endogenous choices of prices and quantities by a cartel of oil exporters, such as the OPEC, can affect the directions of the changes in the likelihood of equilibrium indeterminacy. We show that fluctuations driven by self-fulfilling expectations under oil shocks are easier to occur if the cartel sets the price of oil, but the result is reversed if the cartel sets the quantity of production. These results offer a potentially interesting explanation for the decline in economic volatility (i.e., the Great Moderation) in oil importing countries since the mid-1980s when the OPEC cartel changed its market strategies from setting prices to setting quantities, despite the fact that oil prices are far more volatile today than they were 30 years ago.

OPEC’s oil exporting strategy and macroeconomic (in)stability

Aguiar-Conraria and Wen (2008) argued that dependence on foreign oil raises the likelihood of equilibrium indeterminacy (economic instability) for oil importing countries. We argue that this relation is more subtle. The endogenous choices of prices and quantities by a cartel of oil exporters, such as the OPEC, can affect the directions of the changes in the likelihood of equilibrium indeterminacy. We show that fluctuations driven by self-fulfilling expectations under oil shocks are easier to occur if the cartel sets the price of oil, but the result is reversed if the cartel sets the quantity of production. These results offer a potentially interesting explanation for the decline in economic volatility (i.e., the Great Moderation) in oil importing countries since the mid-1980s when the OPEC cartel changed its market strategies from setting prices to setting quantities, despite the fact that oil prices are far more volatile today than they were 30 years ago.>Organization of Petroleum Exporting Countries ; Petroleum industry and trade

The Continuous Wavelet Transform: A Primer

Wavelet analysis is becoming more popular in the Economics discipline. Until recently, most works have made use of tools associated with the Discrete Wavelet Transform. However, after 2005, there has been a growing body of work in Economics and Finance that makes use of the Continuous Wavelet Transform tools. In this article, we give a self-contained summary on the most relevant theoretical results associated with the Continuous Wavelet Transform, the Cross-Wavelet Transform, the Wavelet Coherency and the Wavelet Phase-Difference. We describe how the transforms are usually implemented in practice and provide some examples. We also introduce the Economists to a new class of analytic wavelets, the Generalized Morse Wavelets, which have some desirable properties and provide an alternative to the Morlet Wavelet. Finally, we provide a user friendly toolbox which will allow any researcher to replicate our results and to use it in his/her own research.Economic cycles; ContinuousWavelet Transform, Cross-Wavelet Transform, Wavelet Coherency, Wavelet Phase-Difference; The Great Moderation.

Understanding the Impact of Oil Shocks

This paper provides new empirical evidence on and theoretical support for the close link between oil prices and aggregate macroeconomic performence in the 1970s. Although this link has been well documented in the empirical literature and is further confirmed in this paper, standard economic models are not able to replicate this link when actual oil prices are used to stimulate the models. In particular, standard models cannot explain the depht of the recession in 1974-75 and the strong revival in 1976-78 based on the oil price movements in that period. This paper argues that a missing multiplier-accelerator mechanism from standard models may hold the key. This multipliplier-accelerator mechanism not only exacerbated the impact of the oil schocks in 1973-74 but also helped create the temporary recovery in 1976-1978. This paper derives the missing multiplier-accelarator mechanism from externalities in general equilibrium. Our calibrated model can explain both the recession in 1974-75 and revival in 1976-78.Oil price shocks, Real business cycle, indeterminacy, capacity utilization, externalities, monopolistic competition.

Referendum Design, Quorum Rules and Turnout

In this article, we focus on the consequences of quorum requirements for turnout in referendums. We use a rational choice, decision theoretic voting model to demonstrate that participation quorums change the incentives some electors face, inducing those who oppose changes in the status quo and expect to be in the minority to abstain. As a result, paradoxically, participation quorums decrease electoral participation. We test our model’s predictions using data for all referendums held in current European Union countries from 1970 until 2007, and show that the existence of a participation quorums increases abstention by more than ten percentage points.Referendum Design; Voter turnout