Tourism demand modelling and forecasting with artificial neural network models: the Mozambique case study

This study is aimed to model and forecast the tourism demand for Mozambique for the period from January 2004 to December 2013 using artificial neural networks models. The number of overnight stays in Hotels was used as representative of the tourism demand. A set of independent variables were experimented in the input of the model, namely: Consumer Price Index, Gross Domestic Product and Exchange Rates, of the outbound tourism markets, South Africa, United State of America, Mozambique, Portugal and the United Kingdom. The best model achieved has 6.5% for Mean Absolute Percentage Error and 0.696 for Pearson correlation coefficient. A model like this with high accuracy of forecast is important for the economic agents to know the future growth of this activity sector, as it is important for stakeholders to provide products, services and infrastructures and for the hotels establishments to adequate its level of capacity to the tourism demand.

Análise de correlação canónica : extensões e aplicações

Neste trabalho apresentamos a teoria da análise de correlação canónica, uma técnica de análise estatística multivariada para o estudo da relação, simultânea, entre dois, três ou mais grupos de variáveis. Descrevemos a natureza da correlação canónica com três ou mais variáveis, com modelos matemáticos, fazendo uma síntese dos métodos de generalização de correlação canónica nomeadamente o método Ssqcor, método Sumcor, método Ecart, método Maxvar, método Minvar, e o método de Carroll. Apresentamos uma aplicação utilizando dados provenientes do cálculo do Índice de Preços no Consumidor IPC, produzido pelo INE - STP (Instituto Nacional de Estatística de São Tomé e Príncipe), referente ao período 2010 a 2014. Estamos interessados em conhecer as correlações canónicas entre grupos de variáveis relacionadas com o cabaz de produtos pré-estabelecido para o cálculo do índice de preços no consumidor, concretamente os produtos alimentares (PA), produtos para bebidas (PB) e produtos não alimentares (PNA), constituindo assim os três grandes grupos de variáveis da nossa pesquisa.

MEDIDAS DE NÚCLEO INFLACIONARIO PARA COSTA RICA

En este documento se elaboran y evalúan medidas alternativas de núcleo inflacionario para Costa Rica. La idea fundamental contempla al núcleo inflacionario como un indicador de la tendencia subyacente de la inflación capaz de capturar el componente del cambio total de precios común a todos los bienes y servicios, cuya persistencia se mantendría en el mediano y largo plazo y que excluye los cambios en los precios relativos de estos. La medida de núcleo inflacionario seleccionada se contrasta con el Índice de Núcleo Inflacionario (INI), indicador de inflación subyacente actualmente utilizado por el Banco Central de Costa Rica (BCCR).El Índice Subyacente de Inflación (ISI), definido como una medida de núcleo inflacionario que excluye un 30,7% del peso total del Índice de Precios al Consumidor (IPC), refleja más fielmente la tendencia subyacente de la inflación y logra capturar el movimiento más permanente del nivel general de precios, aislando las variaciones en precios relativos. Además, el ISI es fácil de calcular e interpretar lo cual ayuda a incrementar la transparencia y credibilidad de la política monetaria. También es un indicador oportuno, aumentando su valor para los que formulan la política monetaria. Por último, el ISI supera algunas de las limitaciones del INI, como son la falta de un criterio estadístico para definir el punto de corte de los bienes y servicios a excluir y el alto porcentaje del peso total del IPC eliminado. AbstractThis paper builds and evaluates several alternative measures of core inflation for Costa Rica. The chosen measure of core inflation is contrasted with the core inflation index (INI), which is the indicator of underlying inflation used today by the Central Bank of Costa Rica (BCCR). The main idea is that core inflation is a good indicator of the underlying inflation and catches the part of overall price change common to all the goods and services that is expected to persist in the medium-term and long-term, and excludes changes in the relative prices of goods and services.The Underlying Inflation Index (ISI) is defined as a measure of core inflation which excludes 30,7% of the total weight of the Consumer Price Index (IPC), it is the most closely related with inflation´s underlying trend and catches the component of overall price change that is expected to persist in the general level of prices. Furthermore, the ISI is easy to compute and to follow, increasing the transparency and credibility of monetary policy and moreover is an timely indicator increasing its value for the monetary policy makers. Finally, the ISI exceed some limitations of INI, as the absence of statistic criterion to define the cutting point of goods and services to exclude and the high percent of total weight eliminated of IPC.

Inflation and the personal distribution of income in Portugal.

Doutoramento em Economia.

Aplicaciones de los modelos de predicción bio-inspirados en la administración

Las organizaciones y sus entornos son sistemas complejos. Tales sistemas son difíciles de comprender y predecir. Pese a ello, la predicción es una tarea fundamental para la gestión empresarial y para la toma de decisiones que implica siempre un riesgo. Los métodos clásicos de predicción (entre los cuales están: la regresión lineal, la Autoregresive Moving Average y el exponential smoothing) establecen supuestos como la linealidad, la estabilidad para ser matemática y computacionalmente tratables. Por diferentes medios, sin embargo, se han demostrado las limitaciones de tales métodos. Pues bien, en las últimas décadas nuevos métodos de predicción han surgido con el fin de abarcar la complejidad de los sistemas organizacionales y sus entornos, antes que evitarla. Entre ellos, los más promisorios son los métodos de predicción bio-inspirados (ej. redes neuronales, algoritmos genéticos /evolutivos y sistemas inmunes artificiales). Este artículo pretende establecer un estado situacional de las aplicaciones actuales y potenciales de los métodos bio-inspirados de predicción en la administración.

Trade practice and price law, federal,

Includes index.

Price and trade: World no tobacco day 2015

This special issue of Tobacco Control for World No Tobacco Day is focused on the theme of Price and Trade.

The role of the terms of trade in the trade channel of transmission of oil price shocks

This paper highlights the role of the terms of trade in the trade channel of propagation of oil price shocks both empirically and theoretically. Empirically, I show that oil price shocks have a large, persistent and statistically significant impact on the US terms of trade. Theoretically, I add oil in the model by Corsetti and Pesenti (2005) and analyse under what conditions the terms of trade plays a relevant role in the international transmission of oil price shocks. With nominal price rigidities and full exchange rate pass-through positive oil price shocks depreciate the currency of the oil importing country. The subsequent negative wealth effect adds to the recessive effect of the supply channel and may trongly reduce the consumption in the oil importing country economy. Without exchange rate pass-through oil shocks transmit to the economy only through the supply channel. The model suggests that a change in the exchange rate pass-through might contribute to explain the evidence of a weaker impact of oil price shocks on the macroeconomic activity in recent times.

Nonparametric estimation of the leverage effect: a trade-off between robustness and efficiency

We consider two new approaches to nonparametric estimation of the leverage effect. The first approach uses stock prices alone. The second approach uses the data on stock prices as well as a certain volatility instrument, such as the CBOE volatility index (VIX) or the Black-Scholes implied volatility. The theoretical justification for the instrument-based estimator relies on a certain invariance property, which can be exploited when high frequency data is available. The price-only estimator is more robust since it is valid under weaker assumptions. However, in the presence of a valid volatility instrument, the price-only estimator is inefficient as the instrument-based estimator has a faster rate of convergence. We consider two empirical applications, in which we study the relationship between the leverage effect and the debt-to-equity ratio, credit risk, and illiquidity.

Time and the price impact of a trade

We use Hasbrouck's (1991) vector autoregressive model for prices and trades to empirically test and assess the role played by the waiting time between consecutive transactions in the process of price formation. We find that as the time duration between transactions decreases, the price impact of trades, the speed of price adjustment to trade‐related information, and the positive autocorrelation of signed trades all increase. This suggests that times when markets are most active are times when there is an increased presence of informed traders; we interpret such markets as having reduced liquidity.

The role of index trading in price formation in the grains and oilseeds markets

We use both Granger-causality and instrumental variables (IV) methods to examine the impact of index fund positions on price returns for the main US grains and oilseed futures markets. Our analysis supports earlier conclusions that Granger-causal impacts are generally not discernible. However, market microstructure theory suggests trading impacts should be instantaneous. IV-based tests for contemporaneous causality provide stronger evidence of price impact. We find even stronger evidence that changes in index positions can help predict future changes in aggregate commodity price indices. This result suggests that changes in index investment are in part driven by information which predicts commodity price changes over the coming months.