The Bioeconomics of Marine Sanctuaries

Consider an offshore fishing grounds of size K. Suppose the grounds has been overfished to the point that net revenue has been driven to zero and the fishery is in open access equilibrium at (X, Y). A marine sanctuary, where fishing is prohibited, is then created. Suppose the marine sanctuary is of size K₂ and that fishing is allowed on a smaller grounds, now of size K₁, where K₁ + K₂ = K. In the first, deterministic, model, the present value of net revenue from the grounds-sanctuary system is maximized subject to migration (diffusion) of fish from the sanctuary to the grounds. The size of the sanctuary is varied, the system is re-optimized, and the populations levels, harvest, and value of the fishery is compared to the 'no-sanctuary' optimum, and the open access equilibrium. In the deterministic model, a marine sanctuary reduces the present value of the fishery relative to the 'ideal' of optimal management of the original grounds. In the second model net growth is subject to stochastic fluctuation. Simulation demonstrates the ability of a marine sanctuary to reduce the variation in biomass on the fishing grounds. Variance reduction in fishable biomass is examined for different-sized sanctuaries when net growth on the grounds and in the sanctuary fluctuate independently and when they are perfectly correlated. For the stochastic model of this paper, sanctuaries ranging in size from 60 to 40% of the original grounds (0.6 K₂/K 0.4) had the ability to lower variation in fishable biomass compared to the no sanctuary case. For a sanctuary equal to or greater than 70% of the original grounds (K₂ 0.7K), net revenue would be nonpositive and there would be no incentive to fish.     

OBESITY AND NUTRIENT CONSUMPTION: A RATIONAL ADDICTION?

Recent research shows that the dramatic rise in obesity in the United States is due more to the overconsumption of unhealthy foods than underactivity. This study tests for an addiction to food nutrients as a potential explanation for the apparent excessive consumption. A random coefficients (mixed) logit model is used to test a multivariate rational addiction model. The results reveal a particularly strong addiction to carbohydrates. The implication of this finding is that price-based policies, sin taxes, or produce subsidies that change the expected future costs and benefits of consuming carbohydrate-intensive foods may be effective in controlling excessive nutrient intake. ( JEL D120, I120, C230)     

Megatrends as perceived in Turkey in comparison to Austria and Germany

Countries and companies use foresight studies to manage uncertainty. Environmental scanning and trend analyses are important tools for identifying and monitoring change. Trend analysis requires more than simply extrapolating to the future. The content of communication serves as the basis of inference so those trends could be explored.This research uses an interdisciplinary approach combining media content analysis and factor analysis to discover many ways Turkey and the world may restructure and what the new society may look like as perceived by the individuals who participated in the survey. It determines six types of individuals in Turkey with different personal attitudes towards megatrends. Similarities and dissimilarities with previous studies in Austria and Germany are identified and discussed.     

Global GDP shares in the 21st century — An equilibrium approach

Using a 9-region model of the world economy, we investigate the implications of the diffusion of total factor productivity (TFP) for global GDP shares during the 21st century. The nine regions are: Africa, Asia (excluding China, India and Japan), China, Europe, India, Japan, Latin America, North America and Oceania. According to our projections, TFP catch-up at a plausible rate implies that the share of the high-income regions will more than halve by 2050 and almost halve again in the subsequent 50 years. These projected shares are little affected by variations in demographic outcomes, saving behaviour and international capital flows, but are reduced substantially should TFP catch-up be slower.     

Analyzing a panel of seasonal time series: Does seasonality in industrial production converge across Europe?

In this paper we consider deterministic seasonal variation in quarterly industrial production for several European countries, and we address the question whether this variation has become more similar across countries over time. Due to economic and institutional factors, one may expect convergence across business cycles. When these have similar characteristics as seasonal cycles, one may perhaps also find convergence in seasonality. To this aim, we propose a method that is based on treating the set of production series as a panel. By testing for the relevant parameter restrictions for moving window samples, we examine the hypothesis of convergence in deterministic seasonality while allowing for seasonal unit roots. Our main empirical finding is that there is no evidence for convergence in seasonality.     

Regional and Sector-specific Determinants of Industry Dynamics and the Displacement–replacement Effects

In this paper, we empirically assess the importance of regional and sector-specific determinants of industry dynamics. To this aim we test three hypotheses (originally proposed by Shapiro and Khemani (1987, Int J Indust Organ 5:15–26)) for the relationship between the entry and exit of firms: independence, symmetry and simultaneity. Estimates from a panel data system of equations seem to confirm the simultaneity hypothesis for Spain, i.e. we find evidence of a displacement (replacement) effect between the gross rate of entry (exit) and the gross rate of exit (entry). Also, our results show that, irrespective of the hypothesis we use, both sectorial and regional variables affect entry and exit.

Value at Risk and Economic Growth

The improvement of data statistics as well as the econometrician methods have facilitated the introduction the new variables and factors I the economic growth analysis. In this sense, real variables have mainly been considered in the economic growth studies, but not financial or risk management aspects. In this sense, it is interesting to analyze the relationship between economic growth and value at risk and the feed-back process. The goal of the paper is to analyze the relationship between economic growth and risk management and the feed-back process. We will consider economic variables, including economic growth, rule of law, human capital, fiscal policy and monetary policy, among others, in our analysis. We will analyze the theoretical relationships between these variables and risk and the effects of risk on economic growth. We will also develop an empirical analysis considering the case of 15 European Union countries.

Demographic waves and labor resources

The author examines the causes, nature, and socioeconomic consequences of medium-term fluctuations in the sizes of age groups in the Soviet Union, with particular attention to the impact on the dynamics of the nation's labor resources. Developments since World War I are outlined, and projections through the end of the twentieth century are summarized. Changes over time in the age distribution of a small population in a Kama River community are used as an example.     

The Effects of Delays on the Stability and Rate of Convergence to Equilibrium of Oligopolies*

The stability of oligopolies is investigated using the Cournot strategy and a general output adjustment procedure. Information delays are incorporated in the adjustment procedure and their specific effects upon the dynamic stability of oligopolies is investigated. The stability of equilibrium for discrete models is unaffected by information delays and remoteness of planning horizons; however the rate of convergence to equilibrium may be slowed. For continuous models with delays, some restraints are required for stability.     

Bank–firms topology in Italy

An empirical analysis of the Italian system of banks and firms is carried out using the network theory. The emerging architecture of this economic network shows peculiar behaviors: (i) Multiple lending is very widespread; (ii) Small firms are preferentially financed by small banks; (iii) Large firms are financed by many banks; (iv) the ratio between loans and deposits is much higher for large banks than for small banks, while (v) strong size heterogeneity appears among co-financing banks, and (vi) the spanning-tree is very hierarchical.