The economics of biotechnology under ecosystem disruption

Economic analysis of chemical pesticide use has shown that the interactions between plants, pests, damage control technology and state of the ecosystem are important variables to be considered. Hence, a bio-economic model was developed for the assessment of Bt variety and pesticide-based control strategies of the cotton-bollworm in China. The model simulates plant growth, the dynamics of pest populations and of natural enemies. The model predictions are used as major inputs for a stochastic micro-level profit model of alternative control strategies.Results show that: (1) productivity effects of Bt varieties and pesticide use depend on the action of natural control agents, and (2) the profitability of damage control measures increases with the severity of ecosystem disruption. The findings highlight the importance of the choice of the counterfactual scenario in the assessment of the impact of agricultural biotechnology. Also, some doubts are raised whether the high benefits of Bt cotton varieties claimed by previous studies based on cross section comparisons are realistic.     

Refuge Strategies for Managing Pest Resistance in Transgenic Agriculture

When the application of pesticides placesselective evolutionary pressure on pestpopulations it can be useful to plant refugeareas: crop areas intended to encourage thebreeding of pests susceptible to the pesticide. Renewed interest in refuge areas has arisenwith recent advances in biotechnology andgenetically modified (GM) crops. This paperuses a simple model of evolution of pestpopulation and pest resistance to characterizethe socially optimal refuge strategy to managepest resistance. We show both that theestablishment of refuge areas might best bedelayed until resistance becomes an importantconcern, and that the use of refuge areas inthe long-run use will not be optimal if thefitness cost of resistance does not exceed thediscount rate.     

Population Genetics and Economic Growth

This paper builds an age-structured model of human population genetics in which explicit individual choices drive the dynamics via sexual selection. In the model, agents are endowed with a high-dimensional genome that determines their cognitive and physical characteristics. Young adults optimally search for a marriage partner, work for firms, consume goods, save for old age and, if married, decide how many children to have. In accord with the fundamental genetic operators, children receive genes from their parents. An agent's human capital (productivity) is an aggregate of the received genetic endowment and environmental influences so that the population of agents and the economy co-evolve. After calibrating the model, we examine the impact of physical, social, and economic institutions on population growth and economic performance. We find that institutional factors significantly impact economic performance by affecting marriage, family size, and the intergenerational transmission of genes. The principal novel findings are that i) genetic diversity has a nonmonotone causal impact on population size and economic performance; ii) an endogenous population threshold exists which, absent frictions, causes societies with declining populations and output to reverse course and grow; and iii) that the emotion love substantially accelerates economic growth by increasing genetic diversity just enough, which we term The Goldilocks Principle.     

Endogenous population with human and physical capital accumulation

This paper proposes an economic growth model with population growth and physical and human capital accumulation. The physical capital accumulation is built on the Solow growth model (Solow in Q J Econ 70:65–94, 1956). The education and human capital accumulation is influenced by the Uzawa–Lucas model (Uzawa in Int Econ Rev 6:18–31, 1965; Lucas in J Monet Econ 22:3–42, 1988). The population dynamics are influenced by the Haavelmo population model (Haavelmo in a study in the theory of economic evolution. Haavelmo, Amsterdam, 1954) and the Barro–Becker fertility choice model (Barro and Becker in Econometrica 57:481–501, 1989). We synthesize these dynamic forces in a compact framework, applying an alternative utility function proposed by Zhang (Econ Lett 42:105–110, 1993). The model describes a dynamic interdependence between population change, wealth accumulation, human capital accumulation, and division of labor. We simulate the model to demonstrate the existence of equilibrium points and to plot the motion of the dynamic system. We also examine the effects of changes in the propensity to have children, the mortality rate parameter, the propensity to receive education, the human capital utilization efficiency, and the mortality rate elasticity of human capital upon dynamic paths of the system.     

A development model of developing economies with capital and knowledge accumulation

This study suggests a model of economic development which treats knowledge accumulation as an endogenous variable. It examines possible dynamic processes in an economic system which accumulates knowledge from developed nations. We describe the dynamics of the system by the interactions of three variables—economic conditions, level of knowledge, and openness. The introduction of openness as an important endogenous variable is due to the fact that the development model considered here is primarily concerned with the economic dynamics of the People's Republic of China. We are especially interested in nonlinear phenomena such as catastrophes and limit cycles. We show that small shifts in political policies may result in great social structural changes.The author is very grateful to two anonymous referees for important comments and to an anonymous referee for linguistic help.     

Cost-effectiveness analysis of implementing an antimicrobial stewardship program in critical care units

Aims: To evaluate the cost-effectiveness of antimicrobial stewardship (AS) program implementation focused on critical care units based on assumptions for the Spanish setting.

Materials and methods: A decision model comparing costs and outcomes of sepsis, community-acquired pneumonia, and nosocomial infections (including catheter-related bacteremia, urinary tract infection, and ventilator-associated pneumonia) in critical care units with or without an AS was designed. Model variables and costs, along with their distributions, were obtained from the literature. The study was performed from the Spanish National Health System (NHS) perspective, including only direct costs. The Incremental Cost-Effectiveness Ratio (ICER) was analysed regarding the ability of the program to reduce multi-drug resistant bacteria. Uncertainty in ICERs was evaluated with probabilistic sensitivity analyses.

Results: In the short-term, implementing an AS reduces the consumption of antimicrobials with a net benefit of €71,738. In the long-term, the maintenance of the program involves an additional cost to the system of €107,569. Cost per avoided resistance was €7,342, and cost-per-life-years gained (LYG) was €9,788. Results from the probabilistic sensitivity analysis showed that there was a more than 90% likelihood that an AS would be cost-effective at a level of €8,000 per LYG.

Limitations: Wide variability of economic results obtained from the implementation of this type of AS program and short information on their impact on patient evolution and any resistance avoided.

Conclusions: Implementing an AS focusing on critical care patients is a long-term cost-effective tool. Implementation costs are amortized by reducing antimicrobial consumption to prevent infection by multidrug-resistant pathogens.     

Online networks,social interaction and segregation: an evolutionary approach

There is growing evidence that face-to-face interaction is declining in many countries, exacerbating the phenomenon of social isolation. On the other hand, social interaction through online networking sites is steeply rising. To analyze these societal dynamics, we have built an evolutionary game model in which agents can choose between three strategies of social participation: 1) interaction via both online social networks and face-to-face encounters; 2) interaction by exclusive means of face-to-face encounters; 3) opting out from both forms of participation in pursuit of social isolation. We illustrate the dynamics of interaction among these three types of agent that the model predicts, in light of the empirical evidence provided by previous literature. We then assess their welfare implications. We show that when online interaction is less gratifying than offline encounters, the dynamics of agents’ rational choices of interaction will lead to the extinction of the sub-population of online networks users, thereby making Facebook and similar platforms disappear in the long run. Furthermore, we show that the higher the propensity for discrimination of those who interact via online social networks and via face-to-face encounters (i.e., their preference for the interaction with agents of their same type), the greater the probability will be that they all will end up choosing social isolation in the long run, making society fall into a “social poverty trap”.     

Evolution in Games with Endogenous Mistake Probabilities

J. Bergin and B. Lipman (Econometrica64 (1996), 943-956) show that the selection effect from the random mutations in the adaptive population dynamics in M. Kandori, G. Mailath, and R. Rob (Econometrica61 (1993), 29-56) and P. Young (Econometrica61 (1993), 57-84) is due to restrictions on how these mutation rates vary across population states. We here model mutation rates as endogenously determined mistake probabilities, by assuming that players with some effort can control the probability of implementing the intended strategy. This is shown to corroborate the results in Kandori-Mailath-Rob (1993) and, under certain regularity conditions, those in Young (1993). Journal of Economic Literature Classification Number: C72.     

The bioeconomics of tritrophic systems: applications to invasive species

Adapted species in nature are assumed to have solved renewable resource management problems, and this is examined here using a physiologically based model of energy acquisition and allocation. Newly established invasive species are merely in an early phase of this process in their new environment. Analogies between the economies of humans and other species are used to develop an objective function for individual utility of energy allocation. The objective function includes the physiologically based population dynamics models of the consumer and resource species in a food chain as constraints. The model applies to all trophic levels in a food chain including human harvesting of renewable resources (see also Regev et al. (Regev, U., Gutierrez, A.P., Schreiber, S., Zilberman, D., 1998. Biological and Economic Foundation of Renewable Resource Exploitation. Ecological Economics. 26 (3), 227-242.)).Specifically, the analysis:

• (1)Attempts to combine ecological and economic theory;
• (2)Points out the importance of time frame in the two economies (evolutionary vs. market time);
• (3)Examines the effects of expected uncertainty due to environmental hazards in defining energy acquisition and allocation strategies in two invasive aphid species at the extremes of so called r- and K-strategies and the well adapted Central American cotton–cotton bollweevil system;
• (4)Evaluates the effects of changes in behavioral and physiological parameters and environmental degradation on the abundance of resource and consumer species.

     

Agent-based modelling of novelty creating behavior and sectoral growth effects—Linking the creative and the destructive side of innovation

For grasping the relationship between novelty creating activities of agents and growth of economic aggregates, a multi-level approach is suggested. The first level specifies the triggering conditions for novelty creating activities for the agents, i.e. firms. Here the behavioral elements and the modes of actions for the firms are portrayed using an agent-based approach (Section?2). On the second level, the consequences of successful innovations and imitations in a given sector of economic activities are dealt with (Section?3). This depends on the frequency of successful novelties and on the way they diffuse in that sector. We use an agent-related functional approach, applying difference equations for depicting the stylized facts of the diffusion dynamics. Only if these different levels of economic dynamics are distinguished as well as related to each other, is it possible to derive aggregate effects of novelties for the whole economy. This will be done by way of computer simulations (Section?4). Conclusions are drawn in Section?5.     

Demographic Transition, Income Distribution, and Economic Growth

This article investigates the dynamic interactions among demographic transition, income distribution, and economic growth. Consistent with empirical evidence we show that fertility and income distribution follow an inverted U-shaped dynamics in the process of economic development. In the first stage fertility increases and income inequality widens, whereas in the second stage fertility declines, income becomes more equally distributed, human capital becomes more abundant, and growth of income per capita takes off. The model therefore generates the documented facts about epochs of demographic transition, relying neither on arguments based on near rationality nor on noneconomic objectives.     

On the level of cooperative behavior in a local-interaction model

We study local interaction within a population located on a connected graph. Subjects engage in several bilateral interactions during each round in a generalized Prisoners' Dilemma (PD). In each round of play one randomly selected player gets the possibility to update the action he plays in this PD. All individuals use the update rule Win Cooperate, Lose Defect, a multi-player variant of Tit-for-Tat. Theoretical results on the set of stable states of the associated dynamics are provided for the cases with and without rare mutations. Simulations provide insight into the probability distribution over these stable states. In both cases a rather high probability is assigned to stable states with a moderate level of cooperation implying that dominated strategies are used. Furthermore, the probability of reaching the stable state with Nash equilibrium play is small.     

Institutionalism and Econometrics: Toward a Meaningful Synthesis

For the last twenty years, the world economy has evolved at a great speed. Every good, capital asset, and knowledge is mobile and induces more competition. Innovation in commodities is a complex process that requires more cooperation. To innovate in the knowledge economy, firms nowadays must establish “win-win situations” for individuals in creating networks. These networks are useful for firms in order to come up with innovative strategies. The building of networks enables the interactions between agents, the environment, and institutions. The interdependence of agents and institutions is not new to evolutionary theory (Commons 1931 Commons, John R. “Institutional Economics.” American Economic Review 21, 4 (1931): 648–657. [Google Scholar]; Veblen 1898 Veblen, Thorstein. “Why Is Economics Not an Evolutionary Sciences?” Quarterly Journal of Economics 12, 2 (1898): 373–397.[Crossref] , [Google Scholar]). However, I argue that institutions must be more flexible than ever before in order to help agents adapt to the modern knowledge economy. On the basis of the role of meso-networks, I propose new long-run specialization and short-run competitiveness that will promote greater efficiency and equality around the world in relation to firms and countries exporting industrial goods into world markets. Within the innovative networks, I analyze the role of two different actors: (i) the “economic leader” who has a long-run strategy and (ii) the “go-between leader” who knows how to diffuse “useful information” to actors to help them innovate in new products, services, or processes.     

The real exchange rate and economic growth: are developing countries different?

Recent research has found a positive relationship between real exchange rate (RER) undervaluation and economic growth. Different rationales for this association have been offered, but they all imply that the mechanisms involved should be stronger in developing countries. Rodrik (2008 Rodrik, D. 2008. The real exchange rate and economic growth. Brookings Papers on Economic Activity, 2: 365–412.  [Google Scholar]) explicitly analyzed and found evidence that the RER–growth relationship is more prevalent in developing countries. We show that his finding is sensitive to the criterion used to divide the sample between developed and developing countries. Using alternative classification criteria and empirical strategies to evaluate the existence of asymmetries between groups of countries, we find that the effect of currency undervaluation on growth is indeed larger and more robust for developing economies. However, the relationship between RER undervaluation and per capita GDP is non-monotonic, and is limited largely to the least developed and richest countries. This discontinuity constitutes a puzzle that calls for closer analysis.     

Shaping the Relationship Between Economic Development and Carbon Dioxide Emissions at the Local Level: Evidence from Spatial Econometric Models

The debate over the correlation between economic growth and environmental pollution has attracted a great deal of attention from academic researchers and policy makers in recent years. There has been excessive use of spatial econometric models and too much emphasis on statistical procedures in empirical studies. In this study, we contribute to the existing literature by conducting a more rigorous analysis of the relationship between economic growth and \(\hbox {CO}_{2}\) emissions in Chinese cities using spatial Durbin models. Our results show that \(\hbox {CO}_{2}\) emissions increase monotonically in relation to economic growth at the city level and that the driving effects of economic growth are slightly smaller in central China than in eastern and western China. In addition to economic growth, industry’s share of the economy is a major driver of \(\hbox {CO}_{2}\) emissions, while technological improvement, measured by energy intensity per unit of gross domestic product (GDP), and the effectiveness of environmental governance flatten the shape of the environmental Kuznets curve. We provide evidence of local spillover effects of explanatory variables on \(\hbox {CO}_{2}\) emissions. Economic competition as well as technological diffusion are found to exist in Chinese cities in relation to \(\hbox {CO}_{2}\) emissions. We also find carbon leakage between cities only if the per capita GDP of a given city is less than $493 (in 2010 constant dollars). Results hold when robustness checks are performed. Policy makers should carefully consider regional differences and the inherent spatial interactions between factors when formulating carbon reduction policies.     

European Monetary Integration and the ‘Constitutionalization’ of Macroeconomic Policy Making

This work discusses the constitutionalization of rules in macroeconomic policy-making in the European Union (EU) with reference to European monetary integration. The analysis deals with two main monetary arrangements, the European Monetary System (EMS) and the Economic and Monetary Union (EMU), and focuses on one country - Italy. Using an interdisciplinary perspective and a constitutional political economy approach, three sets of factors are identified to explain how and why policy-makers may decide to self-limit their sovereignty in monetary and fiscal policies, as they have done in the process of European monetary integration. It is argued that such factors influenced the dynamics and evolution of the European monetary arrangements, shaping the path to EMU.     

Driving economic fluctuations in Peru: the role of the terms of trade

This paper uses a common trend model, following King et al. (Am Econ Rev 81:819–840, 1991), Mellander et al. (J Appl Econ 7(4):369–394, 1992), and Warne (A common trends model: identification, estimation and inference. Seminar Paper 555, Institute for International Economic Studies, Stockholm University, 1993), to evaluate, for 1994–2015, the role of the terms of trade vis-à-vis domestic productivity in explaining macroeconomic fluctuations in Peru. Our results show that Peru’s macroeconomic aggregates share two common trends: an external one, associated with the evolution of the terms of trade; and a domestic one, linked to the evolution of domestic productivity. The external common trend has a larger impact on private investment and public expenditure than on consumption and output, a result consistent with the role of investment in absorbing income volatility. The permanent terms of trade (foreign) shocks account for most of the volatility in output, consumption, private investment, and public expenditure. This result appears more pronounced as the time horizon approaches the long term.     

The Theory of the Individual in Economics: Identity and Value

Fundamental to social provisioning is ensuring that community members have access to employment opportunities that pay living wages and sustain the environment. In a previous study, two of us (Underwood, Friesner and Cross 2014 Underwood, Daniel, Dan Friesner and Jason Cross. “Toward an Institutional Legitimation of Sustainability.” Journal of Economic Issues 48, 3 (2014): 870–885. [Google Scholar]) presented criteria for sustainable community economic development, a three-fold test to comparatively assess economic development policies: ecological holism, community centeredness, and institutional legitimacy. Applying this test generates an iterative, evolutionary process of economic development. Absent from these criteria is the concept of intention, as policy options are not “given,” but rather designed by self-interested groups to manipulate interpretations of these test criteria in advancement of their vested interests — outcomes which can be juxtaposed to the “interests of community.” Here, we integrate two additional principles: economic diversity and solidarity. Economic diversity emphasizes living wages in numerous industries to stabilize exogenous economic shocks. Solidarity, as a unit of socio-economic interdependence, stresses commonality of wellbeing within communities. Integrating solidarity and economic diversity into the criteria for sustainable community economic development improves policy design and outcomes that sustain the environment, while also providing living wage employment for community members.