A Bayesian approach to model changes in volatility in the Mexican stock exchange index

We model the changes in volatility in the Mexican Stock Exchange Index using a Bayesian approach. We study the time series with a wide set of models characterized by a Markov switching heterogeneity. The advantage of this approach is that it allows for a broader spectrum of possible models since the estimation of the moments of the parameters is done using the finite mixture distribution MCMC method, without relying on assumptions about large sampling and mathematical optimization. This is particularly relevant for emerging markets’ financial data because of its special characteristics, like being more susceptible to jumps and changes in volatility caused by exchange rate swings, financial crises and oil and commodity prices. For model comparison, we use the marginal likelihood approach and the bridge sampling technique. The best representation of the data is given by a switching model with three states rather than any other autoregressive linear or non-linear model. The periods of volatility found by the model coincide with different financial crisis. Whereas other studies of volatility for the same market impose the Markovian model that captures changes in volatility, we let our model to be defined in an endogenous way.     

Consumer Motives and Purchase Preferences for Organic Food Products: Empirical Evidence From a Consumer Survey in Bangalore,South India

ABSTRACT

Consumer organic food choice motives and purchase preferences were studied in a structured quantitative survey (N = 201) in Bangalore, with the aim of identifying consumer segments based on these motives and preferences. Further, sociodemographic differences between the clusters were studied. Face-to-face interviews were used to sample the data, which were analyzed with factor and k-means cluster analysis (SPSS 16.0). Five latent factors were identified based on the motives, representing a set of consumer concerns labeled here as “food phobia” (health),” “environment,” “humanity,” “healthy eaters,” and “control.” Further, three clusters emerged from these motives representing 38%, 37%, and 25% of the sample size. The factors differ in terms of variance. Here, the records of perceived healthiness (food phobia) were the most important element, explaining 18.37% of the total variance. These clusters were differing in terms of the level and order of motivations. The health factor was a most important motive in two clusters, followed by environment. Further, humanity was the most important motive for the third cluster. This may reflect a heterogeneous nature of consumers in study area. Additionally, five clusters were identified based on the preferences, and profiles of these clusters differed in terms of sociodemographic factors and consumption pattern. Segments were identified based on motivating factors and preferences, and linking them with food choice motives and products preference provides the input needed by marketing professionals and policy makers to calibrate more efficient marketing strategies to better focus and position their products and design their communication strategies for target segments.     

Trade liberalization and the evolution of skill earnings differentials in Brazil

Skilled labor earnings differentials decreased during the trade liberalization implemented in Brazil from 1988 to 1995. This paper investigates the role of trade liberalization in explaining these relative earnings movements. We perform several independent empirical exercises that check the traditional trade transmission mechanism, using disaggregated data on tariffs, prices, earnings, employment and skill intensity. We find that: i) employment shifted from skilled to unskilled intensive sectors, and each sector increased its relative share of skilled labor; ii) relative prices fell in skill-intensive sectors; iii) tariff changes across sectors were not related to skill intensities, but the pass-through from tariffs to prices was larger in skill-intensive sectors; iv) the decline in skilled earnings differentials mandated by the price variation predicted by trade was even larger than the observed one. The results are compatible with trade liberalization accounting for the observed relative earnings changes in Brazil. They also highlight the importance of considering the effects of differentiated pass-through from tariffs to prices.     

Real Exchange Rate and Economic Growth: New Empirical Evidence

The article empirically analyses the relationship between real exchange rate (RER) and growth rate of output. We first estimate the effect of the index of RER undervaluation on the rate of output growth in two samples of countries from 1978 to 2007. Our contribution is the use of a different dataset that increases the number of countries in the sample, as well as the number of available control variables. In doing so, the article adds to the literature by applying a method that allows for the control of income levels (quantile regressions). So, we present new findings on a non‐linear relationship the RER‐growth nexus. We conclude that maintaining a competitive level of RER has positive effects on growth rate.     

The Trouble with Harrod: The fundamental instability of the warranted rate in the light of the Sraffian Supermultiplier

The paper argues that Harrodian instability is an instance of what Hicks in his book Capital and Growth (1965) called static instability, related to the direction (and not to the intensity) of the disequilibrium adjustment process. We show why such instability obtains in demand‐led growth models in which the ratio of capacity creating private investment to output ratio is given exogenously by the aggregate marginal propensity to save. We also show that Sraffian Supermultiplier model overcomes the Harrodian instability and that its demand‐led equilibrium is statically stable. It is explained that the latter results do not follow from the presence of autonomous non‐capacity creating expenditure component as such but from its presence within a model in which investment is driven by the capital stock adjustment principle (i.e., the flexible accelerator). Finally, we argue that, although being statically stable, the equilibrium growth path of the Sraffian Supermultiplier model can be dynamically stable or unstable depending on the intensity of the reaction of investment to demand. We then provide a discrete time sufficient condition for the dynamic stability of such equilibrium that implies that the marginal propensity to invest remains lower than the marginal propensity to save during the adjustment process, a modified Keynesian stability condition.     

Autocracy,democracy and trade policy

This paper develops a politico-economic model for use in studying the role of intra-elite conflict in the simultaneous determination of a country's political regime, trade policy and income-tax-based redistribution scheme. Three socioeconomic groups are involved: two elite groups and workers, whose preferences regarding trade policy and income taxation are derived from a simple open-economy model. The critical point is that income taxation induces a rich–poor/elite–workers political cleavage, while trade policy opens the door to intra-elite conflict. In this model, when there is no intra-elite conflict, changes in trade policy are associated with political transitions. Coups (democratizations) open up the economy if and only if both elite groups are pro-free-trade (protectionist). However, in the presence of intra-elite conflict, autocracies respond to popular revolts by changing trade policy and reallocating political power within the elite (to the elite group with the same trade policy preference as the workers) rather than offering to democratize the country. The change in trade policy is credible because the elite group with the same trade policy preference as the workers controls the autocracy. Moreover, in the presence of intra-elite conflict, coups tend to result in the maintenance of the existing trade policy unless popular demands are extremely radical and/or the elite group with the same trade policy preference as the workers is exceptionally weak.     

Determinants of Technical Efficiency in Small Firms

There is evidence that small firms are less productive than larger ones. This phenomenon could be explained by several factors. In this paper, using plant survey data and non-parametric deterministic frontier methodology, we explore what factors can explain the observed differences in technical efficiency. In the case of Chilean manufacturing firms, we found that efficiency is positively associated with the experience of workers, modernization of physical capital and innovation in products. In contrast, other variables such as outward orientation, owner education and participation in some public programs do not affect the efficiency of the firms.     

Incentives and creativity: evidence from the academic life sciences

Despite its presumed role as an engine of economic growth, we know surprisingly little about the drivers of scientific creativity. We exploit key differences across funding streams within the academic life sciences to estimate the impact of incentives on the rate and direction of scientific exploration. Specifically, we study the careers of investigators of the Howard Hughes Medical Institute (HHMI), which tolerates early failure, rewards long‐term success, and gives its appointees great freedom to experiment, and grantees from the National Institutes of Health (NIH), who are subject to short review cycles, predefined deliverables, and renewal policies unforgiving of failure. Using a combination of propensity‐score weighting and difference‐in‐differences estimation strategies, we find that HHMI investigators produce high‐impact articles at a much higher rate than a control group of similarly accomplished NIH‐funded scientists. Moreover, the direction of their research changes in ways that suggest the program induces them to explore novel lines of inquiry.     

Analysis of the emergency service applying the queueing theory

Those responsible for the decision-making in hospitals are becoming more aware of the need to efficiently manage hospital systems. One option is the queueing models. In this work, the Emergency service of a public hospital is analyzed by applying the concepts and relations of queues. Based on the results of the model, it is concluded that the Emergency area does not count with the minimum number of doctors necessary for a constant flow of patients. The minimum number of doctors necessary to satisfy the current and future service demand, with the same service times and service disciplines, is calculated using the model. The analytical models allow to directly understand the existing relations between service demand, number of doctors and the attention priority of the patient seen as a system of queues. The work is of use to managers and those responsible for the management of hospital systems.     

Taxing women: A macroeconomic analysis

Based on well-known evidence on labor supply elasticities, several authors have concluded that women should be taxed at lower rates than men. We evaluate the quantitative implications and merits of this proposition. Relative to the current system of taxation, setting a proportional tax rate on married females equal to 4% (8%) increases output and married female labor force participation by about 3.9% (3.4%) and 6.9% (4.0%), respectively. Gender-based taxes improve welfare and are preferred by a majority of households. Nevertheless, welfare gains are higher when the U.S. tax system is replaced by a proportional, gender-neutral income tax.