Baseline Parameterization Research Articles

Efficient Block Designs for Mixed Level Factorial Microarray Experiments based on Baseline Parameterization

A procedure of obtaining efficient block designs in block size 2 for n-factor mixed level factorial microarray experiments based on baseline parameterization has been given. A software module has been developed using C# programming language with ASP.NET platform for generation of efficient block designs in block size 2 for s1 × s2 ×× sn factorial experiments in v −1 arrays, where j s denotes the number of levels of jth factor and n denotes the number of factors and 1 n j j v s = = Π , the total number of treatment combinations. For n = 2, the software developed can also generate efficient block designs for 1 2 v −1≤ b ≤ ( v −1) + ( s −1)( s −1) , where b is the number of arrays.

Documenting and Exchanging Simulation Specifications: A Language-Agnostic Approach

Simulation experiments have increased their influence on social science, creating a need for documentation tools and practices that facilitate replicability. Two crucial components common to many simulation experiments require particularly detailed documentation: the baseline parameterization, and the experimental designs. This paper explores the adaptability to these needs of a recent but already popular file format. It demonstrates how to produce easily human-readable documentation of baseline parameterizations that also supports automated, programming-language agnostic information exchange. This format is additionally useful for documenting certain experimental designs.

Optimal fractions of three-level factorials under a baseline parameterization

The paper proposes the minimum aberration (MA) criterion for three-level designs under a baseline parameterization. An algorithm is put forward to search the MA designs. A catalogue of MA 18-run and 27-run three-level baseline designs is tabulated.

A systematic construction of compromise designs under baseline parameterization

Karunanayaka and Tang (2017) introduced a class of compromise designs for estimating main effects under the baseline parameterization. Their approach is to add some runs to the basic one-factor-at-a-time design, and its implementation requires computer search except for the case of adding one run where a theoretical result is available. The reliance on computer search only allowed them to find the limited results from adding up to four runs to the basic one-factor-at-a-time design. In this paper, we provide a systematic construction of compromise designs, without computer search and without restriction on the run size and the number of factors. Closed-form expressions of the bias and efficiency criteria are obtained for the new designs. Both theoretical and empirical studies show that our designs outperform those of Karunanayaka and Tang (2017) saving small-sized problems.

The Size of U.S. Metropolitan Areas

Metropolitan areas—unions of nearby built-up locations within which people travel on a day-to-day basis among places of residence, employment, and consumption—serve as a fundamental unit of economic analysis. But existing delineations of U.S. metro areas—including metropolitan Core-Based Statistical Areas (CBSAs), Urbanized Areas, and Commuting Zones—stray far from this conception. We develop a flexible algorithm that uses commuting flows among U.S. census tracts in 2000 to match varied interpretations of our metropolitan conception. Under a baseline parameterization that balances encompassing commuting flows and excluding sparsely settled land, our Kernel-Based Metropolitan Areas (KBMAs) capture almost all of the population and employment of metropolitan CBSAs but only a small portion of their land area. The population of the baseline KBMAs is distributed more diffusely than the population of existing delineations, suggesting KBMAs better match the geographic scope of agglomeration. But as with existing delineations, population becomes more bunched across the largest KBMAs. Settled land area expands proportionately with population across small KBMAs but increasingly less than proportionately as population becomes larger, suggesting the existence of centripetal forces that temper the geographic expansion of metropolitan areas.

The Size of U.S. Metropolitan Areas

Metropolitan areas --unions of nearby built-up locations within which people travel on a day-to-day basis among places of residence, employment, and consumption--serve as a fundamental unit of economic analysis. But existing delineations of U.S. metro areas--including metropolitan Core-Based Statistical Areas (CBSAs), Urbanized Areas, and Commuting Zones--stray far from this conception. We develop a flexible algorithm that uses commuting flows among U.S. census tracts in 2000 to match varied interpretations of our metropolitan conception. Under a baseline parameterization that balances encompassing commuting flows and excluding sparsely settled land, our Kernel-Based Metropolitan Areas (KBMAs) capture almost all of the population and employment of metropolitan CBSAs but only a small portion of their land area. The population of the baseline KBMAs is distributed more diffusely than the population of existing delineations, suggesting KBMAs better match the geographic scope of agglomeration. But as with existing delineations, population becomes more bunched across the largest KBMAs. Settled land area expands proportionately with population across small KBMAs but increasingly less than proportionately as population becomes larger, suggesting the existence of centripetal forces that temper the geographic expansion of metropolitan areas.

Pass-through of the policy-induced E85 subsidy: Insights from Hotelling's model

We build a structural model of imperfect competition for a retail market that supplies both low-ethanol (E10) and high-ethanol (E85) gasoline blends. The model permits us to study some impacts of the E85 subsidy induced by the U.S. Renewable Fuel Standard, specifically how the pass-through of this subsidy to retail prices is affected by market power. The model is rooted in Hotelling's horizontal differentiation framework, which is extended to also represent the imperfect substitutability between E10 and E85 (a vertical product differentiation attribute). The model naturally captures two sources of imperfect competition in the fuel market—refueling stations' market power arising from their spatial location, and limited availability of E85 stations. We derive both analytical and numerical solutions for Nash equilibrium outcomes under various scenarios. In our baseline parameterization, when the penetration of E85 stations is incomplete, we find that the pass-through rate is about 0.7. Complete penetration of E85 stations leads to near complete pass-through, notwithstanding the market power enjoyed by stations because of their spatial location. With monopolistic market power (e.g., collusion), however, with full penetration of E85 stations the pass-through rate is lower. Moreover, when market power only arises from location differentiation (duopoly model with full penetration of E85), the pass-through rate converges to one as the subsidy gets large, whereas it converges to zero if a station has exclusivity in selling E85 (partial penetration of E85) or there is collusion/monopoly power from collusion.

Model study on the influence of plant design, photochemistry and meteorology on atmospheric concentrations of nitrosamines and nitramines in vicinity of an amine-based CO2 capture facility

Post combustion using amine solvents is the most mature technology for the capture of CO2 from coal-fired power plants. Yet, amines atmospheric fate and their environmental and human health impacts, after their release by evaporation and solvent degradation from post combustion CO2 capture (PCCC) plants to the surrounding air, remains a key area to address in view of the worldwide installation of large-scale carbon capture and storage facilities. It is therefore crucial to test potential industrial applications with respect to plant design parameters influencing the fate of the amine degradation products. In this work, a method is developed to propose ideal PCCC plant parameters with respect to its design and operation. A risk limiting scenario was modelled on the UK’s largest CO2 capture pilot plant (CCPilot100+) in Ferrybridge using the air dispersion model ADMS, such that the total nitrosamines and nitramines from the amines realised did not exceed the reported atmospheric safety limits of 0.3ng/m3 with respect to human health in the local environment. A parametric sensitivity study was performed to determine the plant design parameters that most influenced the fate of the nitrosamines and nitramines. It was found that stack height and diameter, exit flue gas temperature and velocity are parameters of the PCCC plant can influence the total sum of nitrosamine (NS) and nitramine (NA) from +58% to −42% compared to the baseline parameterization. Environmental parameters, such as the site specific background meteorology and the background photochemistry were also inspected. Meteorology, i.e. mainly wind speed and wind flow field, affected the total NS and NA baseline concentrations from +28% to −10%, and background photochemistry from +165% −65%. In conclusion, if a PCCC plant is constructed with advantageous exhaust geometry, environmentally optimised operation conditions, and placed in an area with low background pollution, the risk associated with employing amines for capturing CO2 emissions might be reduced to a minimum.

Compromise designs under baseline parameterization

We consider estimation of main effects using two-level fractional factorial designs under the baseline parameterization. Previous work in the area indicates that orthogonal arrays are more efficient than one-factor-at-a-time designs whereas the latter are better than the former in terms of minimizing the bias due to non-negligible interactions. Using efficiency criteria, this paper examines a class of compromise designs obtained by adding runs to one-factor-at-a-time designs. A theoretical result is established for the case of adding one run. For adding two or more runs, we develop a complete search algorithm to find optimal compromise designs.

Relative Effects of Labour Taxes and Unemployment Benefits on Hours Worked Per Worker and Employment

AbstractOver the past 3 decades, labour supply in Europe has declined by approximately 30% relative to the USA. The decline comes from hours per worker and employment. The present paper uses a matching model to study the effects of labour taxes and unemployment benefits. Labour taxes decrease hours and employment, with overstated adverse effects on hours if extensive margins are not considered. Unemployment benefits decrease employment and increase hours, with understated adverse effects on employment if intensive margins are not considered. In the baseline parameterization, labour taxes and unemployment benefits together explain approximately 75% of the declining labour supply in Europe relative to the USA.

On the Applicability of Global Approximation Methods for Models with Jump Discontinuities in Policy Functions

We show that the standard Value Function Iteration (VFI) algorithm has difficulties approximating models with jump discontinuities in policy functions. We find that VFI fails to accurately identify the location and size of jump discontinuities while other methods - such as the Endogenous Grid Method (EGM) and a Finite Element Method (FEM) - are much better at approximating this class of models. We illustrate differences across methods using a standard plant-level investment model with both variable and fixed capital adjustment costs. We find that the policy functions generated by VFI are quite different from those generated by EGM and FEM. Importantly, these differences are economically significant: for our baseline parameterization VFI generates investment spikes that are 5-8% larger in comparison to the other two methods. The choice between EGM and FEM depends on the context. While EGM is faster than FEM, it is much more difficult to implement. For larger models, the modifications necessary to apply EGM can lead to high code complexity. On the other hand, FEM can accommodate larger models with minimal implementation differences and its high scalability can reduce computation time significantly.

Optimal fractions of two-level factorials under a baseline parameterization

Two-level fractional factorial designs are considered under a baseline parameterization. The criterion of minimum aberration is formulated in this context and optimal designs under this criterion are investigated. The underlying theory and the concept of isomorphism turn out to be significantly different from their counterparts under orthogonal parameterization, and this is reflected in the optimal designs obtained. Copyright 2012, Oxford University Press.

A modeling framework for integrated harvest and habitat management of North American waterfowl: Case-study of northern pintail metapopulation dynamics

We developed and evaluated the performance of a metapopulation model enabling managers to examine, for the first time, the consequences of alternative management strategies involving habitat conditions and hunting on both harvest opportunity and carrying capacity (i.e., equilibrium population size in the absence of harvest) for migratory waterfowl at a continental scale. Our focus is on the northern pintail ( Anas acuta; hereafter, pintail), which serves as a useful model species to examine the potential for integrating waterfowl harvest and habitat management in North America. We developed submodel structure capturing important processes for pintail populations during breeding, fall migration, winter, and spring migration while encompassing spatial structure representing three core breeding areas and two core nonbreeding areas. A number of continental-scale predictions from our baseline parameterization (e.g., carrying capacity of 5.5 million, equilibrium population size of 2.9 million and harvest rate of 12% at maximum sustained yield [MSY]) were within 10% of those from the pintail harvest strategy under current use by the U.S. Fish and Wildlife Service. To begin investigating the interaction of harvest and habitat management, we examined equilibrium population conditions for pintail at the continental scale across a range of harvest rates while perturbing model parameters to represent: (1) a 10% increase in breeding habitat quality in the Prairie Pothole population (PR); and (2) a 10% increase in nonbreeding habitat quantity along in the Gulf Coast (GC). Based on our model and analysis, a greater increase in carrying capacity and sustainable harvest was seen when increasing a proxy for habitat quality in the Prairie Pothole population. This finding and underlying assumptions must be critically evaluated, however, before specific management recommendations can be made. To make such recommendations, we require (1) extended, refined submodels with additional parameters linking influences of habitat management and environmental conditions to key life-history parameters; (2) a formal sensitivity analysis of the revised model; (3) an integrated population model that incorporates empirical data for estimating key vital rates; and (4) cost estimates for changing these additional parameters through habitat management efforts. We foresee great utility in using an integrated modeling approach to predict habitat and harvest management influences on continental-scale population responses while explicitly considering putative effects of climate change. Such a model could be readily adapted for management of many habitat-limited species.

Moving to High Quality of Life

The U.S. population has been migrating to places with high perceived quality of life. A calibrated general-equilibrium model shows that such migration follows from broad-based technological progress. Rising national wages increase demand for consumption amenities. Under a baseline parameterization, a place with amenities for which individuals would pay 5 percent of their income grows 0.3 percent faster than an otherwise identical place. Productivity is shown to be a decreasingly important determinant of local population. The faster growth of high-amenity places is considerably strengthened if they have low initial equilibrium population density underpinned by low relative productivity. Places with identical amenities asymptotically converge to an identical population density, regardless of their relative productivity levels. An implication is that the high growth rates of high-amenity localities should eventually taper off.

Endogenous Productivity and Development Accounting

Cross-country data reveal that the per capita incomes of the richest countries exceed those of the poorest countries by a factor of thirty-five. We formalize a model with embodied technical change in which newer, more productive vintages of capital coexist with older, less productive vintages. A reduction in the cost of investment raises both the quantity and productivity of capital simultaneously. The model induces a simple relationship between the relative price of investment goods and per capita income. Using cross-country data on the prices of investment goods, we find that the model does fairly well in quantitatively accounting for the observed dispersion in world income. For our baseline parameterization, the model generates thirty-five-fold income gaps and six-fold productivity differences between the richest and poorest countries in our sample.