bluuebunny/crossref_metadata_2025 huggingface dataset:
Mycophagy in small mammals: A comparison of the occurrence and diversity of hypogeal fungi in the diet of the long‐nosed potoroo Potorous tridactylus and the bush rat Rattus fuscipes from southwestern Victoria, Australia
Authors: TORY M. K. , MAY T. W. , KEANE P. J. , BENNETT A. F.
Published: July 2006

Abstract
Three broad dietary categories—fungus, plant and arthropod—were identified from faecal samples of two species of small terrestrial mammal in forest vegetation in southwestern Victoria. Fungal material formed the major component of the diet of the long‐nosed potoroo Potorous tridactylus throughout the year and of the bush rat Rattus fuscipes during autumn and winter. Fungal material was most abundant for both species during autumn and winter and significantly less common in spring and summer. These results confirm previous studies which found P. tridactylus to be highly mycophagous throughout the year and R. fuscipes to be strongly mycophagous seasonally. Particular consideration was given to the composition of fungi in the diet. Fungal spores in faecal material were assigned to spore classes, which represent one or more fungal species that have similar spore morphology. Twenty‐four fungal spore classes were recorded, but for both animal species most of the fungi consumed were from seven major spore classes. The proportions of major spore classes in the diet of both animals were generally similar, even though the composition of spore classes differed markedly across seasons. Minor differences between species in the fungi consumed may be related to differences in selectivity, foraging, or microhabitat use. If fungal resources are limiting, competition for such resources may be important in this and other small mammal communities. The amount and diversity of hypogeal fungi consumed by the two animal species makes them both important spore dispersal agents in forest ecosystems. The capacity of R. fuscipes and other seasonally mycophagous mammals in this role may be more important than previously recognized, especially in habitats where species of the Potoroidae are absent.
Symposium introduction: The importance of scale in ecology
Authors: NALLY R. MAC , QUINN G. P.
Published: July 2006

Abstract
Conceptual issues about scale, both spatial and temporal, have had considerable influence on the way in which ecologists view populations, communities and ecosystems. Scale includes two aspects: the extent over which a community or ecosystem is studied, and the resolution or ‘grain’ at which measurements or experiments are conducted. We illustrate the influence of extent and grain on perceptions of ecological patterns and processes, derived from fundamental measurements, field experiments and theory and modelling. These concepts provide background for a series of subsequent papers that were presented at a symposium on spatial and temporal scaling in freshwater systems. These papers conclude that multi‐scale measurements and experiments plus novel methodologies for analysing large‐scale surveys and manipulations should be priorities for future research in freshwater systems.
Hierarchy, spatial configuration, and nutrient cycling in a desert stream
Authors: FISHER STUART G. , GRIMM NANCY B. , MARTI EUGÉNIA , GÓMEZ ROSA
Published: July 2006

Abstract
Recent studies of nutrient cycling in Sycamore Creek in Arizona, USA, suggest that a thorough understanding requires a spatially explicit, hierarchical approach. Physical configuration determines the path that water follows as it moves downstream. Water follows flowpaths through surface stream components, the hyporheic zone beneath the surface stream, and the parafluvial (sand bar) zone. Characteristic biogeochemical processes in these subsystems alter nitrogen (N) species in transport, in part as a function of available concentrations of N species. At several hierarchical levels, substrate materials are an important determinant of nitrogen dynamics in desert streams. Sand is present in bars of variable size and shape, each of which can be considered a unit, interacting with the surface stream. Groups of these stream‐sandbar units form a higher level, the reach. At the next higher scale, sandy reaches (runs) alternate with riffles. Where flowpaths converge, rates of N transformation are high and, as a result, change in concentration is a non‐linear function of flowpath length. Disturbance by flash floods alters sandbar configuration. Between floods, the interaction of subsurface and surface flowpaths shapes configuration in each, thus a self‐organizing element of spatial structure exists. Sandy runs are dominated by subsurface processes and are likely to be net nitrifiers while riffles are dominated by surface flow and are nitrogen fixers. Whether a stream ecosystem retains nitrogen, or transports it to downstream recipient systems, or is a net emitter of gaseous forms of N, depends upon the dynamics of a spatial mosaic of interacting elements. An understanding of the net effect of this mosaic requires a spatially explicit, hierarchical, multi‐scale approach.
Predictive models in spatially and temporally variable freshwater systems
Authors: HARRIS GRAHAM P.
Published: July 2006

AbstractThis paper discusses the relationships between scaling and predictability in ecosystems. The logical basis of ecosystem modelling is explored using ideas first developed in complexity theory and analogies with the behaviour of complex adaptive systems. Any ecological model is a scale‐dependent entity and both empirical and dynamic models of freshwater systems have their strengths and weaknesses. The logical basis of modelling using functional groups is explored. I conclude that such an approach can be justified and that such models have predictive power. Any predictive model of freshwater systems must take the major scales of external (atmospheric and catchment) forcing into account as well as the scales of key processes in the ecosystem itself. The importance of so‐called ‘pink noise’ spectra, which arise both from external forcing and the internal dynamics of dynamic systems, is noted. The key scales of pattern and process in freshwater ecosystems are discussed in relation to the properties of the major functional groups. In order to have predictive power, I conclude that models of freshwater systems must include sediment exchanges and the properties of aquatic macrophytes as well as water column interactions and the pelagic components. When viewed at the scale of functional groups and the major biogeochemical processes, freshwater ecosystems may not be as complex as is often assumed.
Partitioning the variation among spatial, temporal and environmental components in a multivariate data set
Authors: Anderson M. J. , Cribble N. A.
Published: July 2006

Abstract We propose a method of partitioning the variation in a multivariate set of data according to (i) environmental variables, (ii) variables describing the spatial structure in the data and (iii) temporal variables. This method is an extension of an existing method for partialling out the spatial component of environmental variation, using canonical analysis. Our proposed method extends this approach by including temporal variables in the analysis. Thus, the partitioning of variation for a data matrix of species’abundances or biomass can include, by our methodology, the following components: (1) pure environmental, (2) pure spatial, (3) pure temporal, (4) pure spatial component of environmental, (5) pure temporal component of environmental, (6) pure combined spatial/temporal component, (7) combined spatial/temporal component of environmental and (8) unexplained. In addition, permutation testing accompanying the analyses allows tests of significance for the relationship between the different components and the species data. We illustrate the method with a set of survey data of penaeid species (prawns) obtained on the far northern Great Barrier Reef, Australia. This extension is a useful tool for multivariate analysis of ecological data from surveys, where space, time and environment commonly overlap and are important influences on observed variation.
Assessing early recruitment dynamics and its demographic consequences among tropical reef fishes: Accommodating variation in recruitment seasonally and longevity
Authors: ROBERTSON D. ROSS , KAUFMANN KARL W.
Published: July 2006

Abstract When settlement of pelagic juveniles of reef fishes is highly and predictably seasonal, annual, end‐of‐season surveys of surviving recruits (which are commonly used on the Great Barrier Reef) are useful for assessing recruitment dynamics and their demographic effects. However, when settlement is continuous or weakly seasonal, with patterns that vary both between species and within species among years, regular, sometimes year‐round, recruitment surveys at intervals linked to short‐term settlement dynamics are needed to quantify fluctuations in recruitment strength. Monthly recruitment surveys may be appropriate in the tropical northwest Atlantic, where settlement is often both lunar periodic, and broadly and variably seasonal. Use of a variety of recruit‐census methods impedes comparisons of recruitment patterns and their demographic effects, because recruit densities and recruit:adult ratios cannot be directly compared when recruits (because they have widely varying post‐settlement ages) have experienced very different levels of early post‐settlement mortality. Examining the relationship between changes in adult populations and annual, end‐of‐season recruitment may be satisfactory for long‐lived species with strong settlement seasonality and maturation times of approximately 1 year. However, it is inappropriate for short‐lived, rapidly maturing species, particularly those that have broad and variable settlement seasons and whose populations fluctuate substantially throughout the year in response to short‐term fluctuations in recruitment. Comparisons of demographic effects of recruitment among species with different longevity require the use of non‐arbitrary time scales, such as the time to maturity and the adult half‐life.
Scaling eutrophication effects between species and ecosystems: The importance of variation and similarity among species with similar functional roles
Authors: BREITBURG DENISE L.
Published: July 2006

Abstract Although eutrophication is frequently cited as an anthropogenic threat to coral‐reef systems, very little is known about the effects of eutrophication on coral‐reef fishes. In this paper, I explore how variation and similarity among fish species, and among the species with which they interact, may determine when population‐ or system‐level responses to nutrient enrichment are most likely. Where functionally similar species exhibit complementary responses to environmental stress, ecosystem function may be maintained relatively unchanged although the relative abundance of species may shift dramatically. Alternatively, major changes in the ecosystem can occur if functionally similar species respond similarly to changes in the environment, if little functional complementarity or behavioural plasticity exists, or if feedback exists whereby changes in the fish assemblage cause further degradation of their coral habitat.
Pasture management in semi‐arid tropical woodlands: Effects on species diversity
Authors: McIVOR JOHN G.
Published: July 2006

Abstract The effects of pasture management options (sowing introduced legumes and grasses, timber treatment, applying fertilizer, cultivation before sowing, and stocking rate) on species diversity were measured at two experimental sites (Hillgrove and Cardigan) near Charters Towers, northeast Queensland. Species were divided into three groups (sown, native and exotic) and diversity was measured as species density (number of species recorded in each plot and number of species/quadrat) annually from 1982 to 1992. The responses of individual native and naturalized species to treatment were also determined. All management options affected diversity but the responses varied with site and season, and with the different measurement scales. The density of sown species either increased or was unaffected by all the management options; there were no significant decreases. The density of native species showed both positive and negative responses; it increased at high stocking rates and with tree killing at Hillgrove, and decreased with pasture sowing and cultivation. The density of exotic species increased as stocking rate was increased and decreased when pastures were sown (although not at the quadrat scale at Hillgrove). Overall the most diverse vegetation was on plots grazed at high stocking rates; at the plot scale these were native pastures but at the quadrat scale the sown pastures had more species. Among the native and naturalized species, only Portulaca spp. were more frequent on the oversown plots than the native pasture plots; 48% (Hillgrove) and 68% (Cardigan) of the species were less frequent on the oversown plots. Fertilizer application had little effect on species frequencies, while timber treatment resulted in both increases and decreases in frequency of a small number of species. The species were divided into four groups on the basis of their responses to stocking rate: a grazing‐sensitive group (e.g. Themeda triandra), two grazing‐tolerant groups which either slightly decreased (e.g. Chrysopogon fallax) or slightly increased (e.g. Sida spinosa) in frequency as stocking rate increased, and a fourth group of species which were frequent only at high stocking rates (e.g. Bothriochloa pertusa). There were no close relationships between herbage yield and species density.
Quantitative sampling of stream fish assemblages: Single‐ vs multiple‐pass electrofishing
Authors: PUSEY BRADLEY J. , KENNARD MARK J. , ARTHUR JAMES M. , ARTHINGTON ANGELA H.
Published: July 2006

AbstractStream fish assemblages were sampled by multiple‐pass electrofishing and supplementary seine netting in 31 sites in the Johnstone River, north Queensland and 28 sites in the Mary River, southeastern Queensland to determine the sampling effort required to adequately describe the assemblages in terms of fish abundances, species composition and assemblage structure. A significantly greater proportion of the total number of fishes present at each site was collected by the first electrofishing pass in the Mary River (46%) than in the Johnstone River (37%) and this difference was suggested to be due to higher water conductivity in the former river. The mean proportion of the total species richness detected by the first pass was also significantly higher in the Mary River than in the Johnstone River (89% and 82%, respectively). Multivariate comparisons offish assemblage structure revealed that data collected by the first electrofishing pass poorly estimated the actual assemblage structure within a site and that up to three passes were required for estimates of assemblage structure to stabilize. This effect was evident for comparisons based on both absolute abundance and relative abundance data and was particularly marked for comparisons based on presence/absence data. This latter result suggests that, even though most species were detected on the first pass, the addition of rare species by subsequent passes had an important effect on the resultant description of assemblage structure. Supplementary seine netting had a greater effect on the determination of assemblage structure in the Mary River than in the Johnstone River. The results are discussed with reference to sampling design in studies of stream fish assemblages and a sampling protocol is recommended that enables the accurate determination of abundance, richness and assemblage structure in small‐ to medium‐sized streams.
Density‐dependent germination and the role of seed leachate
Authors: MURRAY BRAD R.
Published: July 2006

Abstract While density dependence is a central issue in much of plant ecology, it is often overlooked during the crucial seed germination period of the plant life‐cycle. Here, patterns of germination in relation to initial seed density for 12 phylogenetically‐diverse perennial plant species are described from laboratory experiments. When each of the 12 species was analysed individually, seeds of Alysicarpus rugosus, Callistemon citrinus, Eragrostis curvula and Panicum miliaceum showed a significant decrease in the proportion of seeds germinating at high densities of conspecifics. A meta‐analysis carried out by grouping 11 of the 12 species together revealed an overall significant effect for a decrease in the proportion of seeds germinating at high conspecific densities compared with low con‐specific densities. Significant decreases in the proportion of seeds germinating are interpreted as risk reappraisal by seeds through dormancy in response to potentially hazardous conditions imposed by high density clusters of seeds all germinating at once. The four species that responded significantly to high densities individually were each treated at low densities with a leachate solution obtained from high density conspecifics. For Alysicarpus rugosus and Panicum miliaceum, this resulted in a significant decrease in the proportion of seeds germinating at simulated high densities implicating the leachate as a causative agent. Heterospecific effects were investigated similarly for A. rugosus and E. curvula by the addition of leachate from high density clusters of seeds of one species upon the other. Only A. rugosus decreased germination significantly through the addition of leachate. These results demonstrate the ability of seeds to predict environmental conditions of the habitat into which they will emerge in terms of potential competitive interactions from neighbouring seedlings.
The foraging profile of a wandoo woodland avifauna in early spring
Authors: RECHER HARRY F. , DAVIS WILLIAM E.
Published: July 2006

Abstract This study reports on the foraging profile of a wandoo woodland avifauna at Dryandra in Western Australia, Australia. Despite its geographical isolation, wandoo woodland shares a large number of species with woodland bird communities in eastern Australia and there are broad similarities in community foraging profiles. Insect‐eating birds using ground, bark, foliage, and aerial substrates dominate eucalypt bird communities. Nectar‐feeding and seed/fruit‐eating guilds are important components of the Australian avifauna, but have fewer species, and vary in composition and abundance as nectar, seed, and fruit availability changes seasonally and from year to year, and from one locality to another. Despite similarities, there are also differences between the foraging profile of the wandoo avifauna and those in eastern Australia. Specifically, the wandoo avifauna is characterized by a high proportion of ground‐foraging species. In addition, many wandoo woodland birds appear to spread their foraging over a wider range of substrates (i.e., ground, bark, and foliage) than eastern species. Differences in habitat structure do not explain these differences in community foraging profiles, and there may be differences in the abundance, kind, and spatial distribution of resources between different eucalypt ecosystems. Possibly the eastern communities have lost ground‐dwelling components of their avifauna since European settlement, while the woodlands at Dryandra retain a more intact avifauna. The reasons why some species and not others are lost from woodlands as a result of European land management practices are discussed.
Shrub succession and invasibility in a New Zealand montane grassland
Authors: BELLINGHAM P. J.
Published: July 2006

AbstractTwo successive shrub invasions of a short tussock grassland induced by grazing and burning were examined in montane South Island, New Zealand. The first invasion was by a native shrub, matagouri (Discaria toumatouRaoul). The second invasion was by an exotic shrub, Scotch broom (Cytisus scoparius(L.) Link), which invaded the matagouri shrubland that had developed over the grassland. The invasions were investigated using analysis of spatial patterns of both shrubs and tussocks, and age, growth rates and size structure of the shrubs. Competition between the two shrub species was examined using spatial patterns and comparing allometric relationships. After initial invasion by matagouri of the grasslands, stand density increased by consolidation about its initial colonization points. Current matagouri distribution is often negatively associated with tussocks. Scotch broom occurs most frequently in a dense sward of introduced grasses and occasionally in tussocks in interstices among matagouri shrubs. Despite the palatability of Scotch broom to sheep that graze the site, there was no evidence that the spiny matagouri facilitates invasion by protecting Scotch broom seedlings; rather there was negative association between the shrub species. The two species probably compete for above‐ground space. However, diameter and height growth rates of Scotch broom far exceed those of matagouri so Scotch broom is likely to increase in biomass rapidly at the site. The autogenic organization and disturbance history of the resident plant communities have rendered each vulnerable to successive invasions.
Risk assessment of an exotic biocontrol agent: Phytoseiulus persimilis (Acari: Phytoseiidae) does not establish in rainforest in southeast Queensland
Authors: WALTER DAVID EVANS , AZAM GOLAM NABI , WAITE GEOFF , HARGREAVES JOHN
Published: July 2006

Abstract The Chilean predatory mite, Phytoseiulus persimilis Athias‐Henriot, appeared in Australia in 1978 soon after being introduced into New Zealand as a specialized biological control agent of spider mites. It is known to be naturalized in agricultural habitats in southeast Queensland, Australia, although nothing is known about its distribution in native ecosystems. In order to determine whether P. persimilis is able to invade subtropical rainforest, we placed potted bean plants infested with its preferred prey, the two‐spotted mite (Tetranychus urticae C.L. Koch), at 50 m intervals for 200 m on either side of the rainforest‐field ecotone at four sites in southeast Queensland. Two, 4 and 6 weeks after placement, five leaves were sampled from each pot and any phytoseiid mites present were identified. The initial experiment took place in the spring and was repeated in summer and in autumn of 1997. At all four sites and in all three seasons P. persimilis rapidly colonized all of the pots in fields. In the rainforest, however, some pots were never colonized and significant populations of the predator developed only in the summer, and then only at the first stations, 50 m into the forest. These results suggest that even when its preferred prey is present, subtropical rainforest is not an appropriate habitat for P. persimilis. In addition, we reviewed extensive collections of phytoseiid mites from native forests and synanthropic habitats in Australia and found P. persimilis records only from fields, glasshouses, gardens, weeds, roadsides and similar disturbed habitats dominated by introduced plants, again suggesting that this biocontrol agent is not a rainforest invader.
PRICE UNCERTAINTY, FACTOR SUBSTITUTION, AND THE LOCATIONAL BIAS OF BUSINESS TAXES*
Authors: Martinich Joseph S. , Hurter Arthur P.
Published: July 2006

Consideration of the integrated production‐location problem is extended to include several types of business taxes. Many of these taxes are technologically and spatially neutral under certainty, but are shown to be nonneutral when factor prices are stochastic and the firm is risk averse, even when the tax is spatially uniform. Consequently, even a nationally uniform tax can have regional biases and can encourage migration of plants. When factor prices are uncertain, the effects of taxes on output rates, input ratios, and plant location vary with the form of the tax imposed as well as the amount to be paid. Income taxes involve the taxing authority in sharing the risk with the firm and are shown to promote risk taking by the firm and induce the expansion of output. Locational incentives which are mutually beneficial to firms and the government are presented.
NON‐NESTED TESTS ON THE WEIGHT STRUCTURE IN SPATIAL AUTOREGRESSIVE MODELS: SOME MONTE CARLO RESULTS*
Authors: Anselin Luc
Published: July 2006

ABSTRACT.This paper presents some further results with respect to hypothesis tests for the appropriate structure of dependence in mixed regressive/spatial‐autoregressive relations. Three tests on non‐nested hypotheses are considered, which are based on the use of augmented regressions, and their small sample performance is compared in a number of Monte Carlo simulation experiments.
THE DETERMINANTS OF COUNTY GROWTH*
Authors: Carlino Gerald A. , Mills Edwin S.
Published: July 2006

ABSTRACT. This paper explores the determinants of population and employment densities interregionally. The theoretical model, due to Steinnes and Fisher, permits simultaneous determination of population and employment densities. This is applied to data for about 3,000 counties in the U.S. to analyze the effects of economic, demographic, climatic, and policy‐related variables on the growth of population and employment, during the 1970s. Considering employment, differential county growth is explained in terms of economic and demographic conditions; regional and policy variables matter less. For population, climate matters as a preference for sunbelt states is found. Local government programs regarding education and tax policy seem to play a role.
REGIONAL CAPITAL FORMATION IN U. S. MANUFACTURING DURING THE 1970s
Authors: Garofalo Gasper A. , Malhotra Devinder M.
Published: July 2006

ABSTRACT The study quantifies the impact of changes in input prices on regional net investment in manufacturing. A neoclassical investment model is estimated for the nation and three regions: North, South, and West. The data base is pooled state observations for the period 1974‐78. The regional elasticities of net investment with respect to both input prices and the technology index are computed. The results indicate that net investment is mare sensitive to changes in input prices in the South and West than in the North. The biased technical change affects capital formation the mast in the West.
A NOTE ON INCOME TAXES AND DEGREE ONE PRODUCTION HOMOGENEITY*
Authors: Martinich Joseph S. , Hurter Arthur P.
Published: July 2006

ABSTRACT In a recent JRS article [Martinich and Hurter (1985)] we examined the production and spatial impact on a firm operating in an uncertain environment due to the imposition of a flat rate income tax. The impacts were shown to depend on the properties of the firm's production and preference functions. In this paper we develop further results for the case where the firm has a degree one homogeneous production function. It is shown that an income tax is technologically and spatially neutral for any risk‐averse firm, without regard to any other properties of the preference function. Thus, we not only extend our earlier results for the degree one homogenous production function case but we also correct an error related to this case in the earlier paper.
A NOTE ON SPECIFICATION OF CLIMATE VARIABLES IN MODELS OF POPULATION MIGRATION*
Authors: Cushing Brian J.
Published: July 2006

ABSTRACTIn the literature on population migration, increasing attention has been devoted to quality‐of‐life factors. Measures of temperature (as proxies for climate) have frequently been employed in empirical work regarding the determinants of population migration decisions. A wide range of such specifications have been used, most of which imply restrictions on the preferences of migrants. In this paper, a variety of temperature variable specifications are analyzed and interpreted. Statistical tests for nested and nonnested hypotheses are used to compare and choose among the various specifications.
THE DISTRIBUTION OF SERVICE ESTABLISHMENTS*
Authors: Stephan G. Edward
Published: July 2006

ABSTRACT All previous theory and research have led to the expectation that the density of service establishments will be proportional to the 2/3 power of the density of the population served by them. Study of the distribution of over 400 nongovernmental establishments refutes this expectation for such cases. A previous derivation from time minimization theory is reformulated to encompass these new findings.
THE OUTPUT EFFECTS OF SPATIAL PRICE DISCRIMINATION REVISITED*
Authors: Ohta H. , Wako T.
Published: July 2006

ABSTRACT Some prior findings on spatial price discrimination are extended. Under certain spatially defined market conditions, discriminatory pricing is known to yield greater output than does nondiscriminatory f.o.b. mill pricing. However, this seemingly surprising result is based on the form of the basic demand function which is relatively less convex than a certain standard curve. The present paper makes this prior result more general by permitting the assumed basic demand to be relatively more convex.
THE MOSES‐PREDOHL PULL AND THE LOCATION DECISION OF THE FIRM*
Authors: Pace Kelley , Shieh Yeung‐Nan
Published: July 2006

ABSTRACTThis paper exploits the two‐stage approach and the envelope theorem to examine the role of the Moses‐Predhol pull in the cost‐minimizing location theory of the firm. It shows that the two‐stage approach introduces the Moses‐Predohl pull into the first‐order conditions. The Moses‐Predohl pull is shown to be equal to zero through the envelope theorem. These results show why the assertions of Bossert and Buhl (1986) concerning Kusumoto (1984,1985) are incorrect.
INTERRELATIONAL INCOME‐DISTRIBUTION MULTIPLIERS FOR THE WEST VIRGINIA ECONOMY*
Authors: Rose Adam , Beaumont Paul
Published: July 2006

ABSTRACT. This paper presents a set of Miyazawa interrelational multipliers, which measure how direct changes in the income of each income bracket result in indirect and induced income changes in all other brackets. The multipliers have been calculated for a 9‐by‐9 pairing of income brackets for West Virginia in 1982. Their estimation is based on a combination of survey and nonsurvey data in three forms: a 1982 West Virginia input‐output table, a multisector income‐distribution matrix, and an income disaggregated consumption matrix. The paper illustrates the usefulness of the multipliers by showing how they provide insight into the viability of trickle‐down theory and the incidence of regional development policy.
USING A COMPOSED ERROR MODEL TO ESTIMATE THE FRICTIONAL AND EXCESS‐SUPPLY COMPONENTS OF UNEMPLOYMENT
Authors: Hofler Richard A. , Murphy Kevin J.
Published: July 2006

ABSTRACT We present in this paper a plausible and simple method of estimating the two components (frictional and excess supply) of unemployment. This approach uses a stochastic model whose error term is composed of two elements–the usual two‐sided error and a one‐sided error. Our method has several strengths. First, we are able to explicitly model the universally held view that there is a nonzero lower bound on unemployment. Second, we can easily determine whether each region's unemployment rate is caused primarily by excess supply or frictional forces. We illustrate our technique on a data set comprised of all 50 states over the period 1960‐1979. Finally, estimation of the frictional rates of unemployment allows us to analyze, in the last part of the paper, the underlying economic and demographic determinants of differences in frictional unemployment rates across states and over time.
NEOCLASSICAL AND KEYNESIAN PERSPECTIVES ON THE REGIONAL MACRO‐ECONOMY: A COMPUTABLE GENERAL EQUILIBRIUM APPROACH*
Authors: Harrigan Frank , McGregor Peter G.
Published: July 2006

ABSTRACT Regional economic models typically either ignore prices altogether or simply treat them as exogenously determined. An unfortunate consequence of the neglect of prices is that model builders have been very much limited in the range of macroeconomic perspectives they have been able to bring to bear on regional economic issues. In this paper, we first explain how prices can be modeled endogenously at a regional level despite the paucity of data on regional prices. Using an illustrative interregional computable general equilibrium model for Malaysia, we then demonstrate how alternative macroeconomic visions of regional systems may be captured.
THE RELATIONSHIPS AMONG LABOR‐FORCE PARTICIPATION, SERVICE‐SECTOR EMPLOYMENT, AND UNDEREMPLOYMENT*
Authors: Nord Stephen
Published: July 2006

ABSTRACT. In this study, it is argued the underemployment is both affected by and affects the labor‐force participation rate (LFPR) and the level of service employment. Interestingly, the analysis reveals that service employment lowers the LFPR and raises underemployment. In turn, underemployment increases the LFPR as more secondary workers are pushed into the labor market in an effort to support their households. Thus, secondary workers are not pulled into the labor market by the availability of service jobs, but are rather pushed into these jobs by the condition of underemployment that is brought on by the growing concentration of low‐paying service jobs.
TESTING CRITERIA FOR DETERMINING LEADING REGIONS IN WAGE TRANSMISSION MODELS*
Authors: Lesage James P. , Reed J. David
Published: July 2006

In this study, we use a vector autoregressive modeling framework to test the zero restrictions implied by alternative criteria for ranking regions into hierarchies in the wage‐transmission debate. This approach allows formal statistical tests to be carried out for competing criteria suggested for determining leading and following regions.

The ability of the modeling technique proposed here to produce a set of nested hypothesis tests of alternative criteria is in stark contrast to the historical literature in this debate. Researchers have traditionally proposed a criterion for ranking regions into a hierarchy, and then argued for the merits of their particular criterion by demonstrating that an econometric model of wage formation produces statistically significant coefficient estimates when their criterion is used to rank the regions of their data sample.

We apply the methods proposed here to a sample of eight midwestern cities in the U.S. in order to test the following criteria: Beaumont (1983), Hart and MacKay (1977), Reed and Hutchinson (1976), unemployment rate, and earnings level. The test is for consistency with the Granger‐causal structure of wage interactions inherent in the wage diffusion idea. We argue that the technique set forth here is a real step forward that should allow a resolution of this particular debate. The proposed procedures might also be applied to empirically test other regional science hypotheses concerning for example, intercity and interindustry causal structures.
COMPETITION AND CEMENT BASING POINTS: F.O.B. DESTINATION, DELIVERED FROM WHERE?*
Authors: Karlson Stephen H.
Published: July 2006

Spatial price theory suggests that locations which become basing points do so in response to competitive forces. The paper presents a model that captures the effect of those forces. When the model is tested against a sample of cement mills, there is little support for the competitive hypothesis. There is some evidence that the large cement producers determined which locations became basing points.
HEDONIC PRICES, IDENTIFICATION, AND THE DEMAND FOR PUBLIC SAFETY*
Authors: Clark David E. , Cosgrove James C.
Published: July 2006

In this paper, we use a two‐stage intercity hedonic model to estimate household demand for public safety. This approach is shown to readily address the identification problem inherent in the hedonic model. Data from the 1980 Public Use Microdata Sample are used to estimate a willingness‐to‐pay function for the public‐safety good. Income is found to be the primary determinant of willingness to pay. Indeed, the influence of income outweighs the combined impact of family life‐cycle considerations.
LOCAL STATUS AND NATIONAL SOCIAL WELFARE
Authors: Persky Joseph , Tam Mo‐Yin
Published: July 2006

Perceptions of individual well‐being are influenced by local status, i.e., one's place in the income distribution of one's reference group. In general, reference groups are smaller than the entire nation. If national social welfare is an aggregate of individual's well‐being, then it is not symmetric with respect to all individuals. A geographical interpretation of reference groups means that the welfare of a family living in one region is only influenced by other families in that region. An empirical application, using states, shows that a Gini index modified to reflect local status showed much less improvement 1949‐1979 than did the standard Gini.
FORECASTING METROPOLITAN EMPLOYMENT USING AN EXPORT‐BASE ERROR‐CORBECTION MODEL
Authors: LeSage James P.
Published: July 2006

This paper shows that a time‐series version of export‐based location quotients, which decompose area employment into export and local components are co‐integrated. Given the statistically established co‐integrating relation between the time series for export and local employment, the Granger Representation Theorem tells us that an error‐correction mechanism model is the appropriate time‐series model specification. A set of forecasting experiments is carried out, in order to test whether the error‐correction model produces better long‐run forecasts that hold together in economically meaningful ways. Given the computer hardware and software that currently exist, the model developed here represents a simple, low‐cost method for accurately forecasting local‐area employment in the tradition of past work on export‐base models.
DEFENSE SPENDING AND STATE ECONOMIC GROWTH*
Authors: Mehay Stephen L. , Solnick Loren M.
Published: July 2006

Little evidence is currently available on the regional growth effects of federal defense spending. In this study, econometric models for state personal income and manufacturing employment between 1976 and 1985 are specified and estimated. Pooled cross‐sectional time‐series data are used, and the estimation procedure corrects for serial correlation, heteroscedasticity, and contemporaneous cross‐sectional correlation. The results indicate that aggregate defense spending has a positive effect on both growth measures. However, when defense expenditures are disaggregated, only investment‐type outlays appear to consistently affect state economic growth.
MARKET DEFINITION AND ASSESSING THE COMPETITIVE RELATIONSHIP BETWEEN RAIL AND TRUCK TRANSPORTATION*
Authors: Buckley Patricia , Westbrook M. Daniel
Published: July 2006

ABSTRACT. In this paper we develop a method for establishing market definition in studies of intermodal competition. We employ the proposed method in a transportation model that yields estimates of the substitutability between truck and rail services for the transport of fresh fruits and vegetables. The model includes the produce being shipped as an input into the production of delivered produce. Our results demonstrate that fairly disaggregate market definitions are required to characterize adequately the intermodal substitution possibilities of interest. While disaggregate data are required for econometric estimation of the cost function, it is essential that elasticities be calculated at a disaggregate level as well. The elasticities reported are larger than reported in earlier work and provide strong evidence of vigorous intermodal competition in produce transportation markets.
UNCERTAIN INCOME AND HOUSING PRICE AND LOCATION CHOICE*
Authors: Turnbull Geoffrey K. , Glascock John L. , Sirmans C. F.
Published: July 2006

ABSTRACT. In this paper, we adapt recent developments in uncertainty modeling to the location choice paradigm. In particular, we analyze the impact of income and housing price uncertainty on housing demand and location demand characteristics in a partial equilibrium framework. We begin by recognizing that housing consumption cannot readily be altered in response to changes in income and price. We find that income and house price risk affect housing and location demands in different ways. Additionally, the spatial characteristics of price risk also affect consumer housing and location demands. For example, if housing price risk is lower farther from the central city, housing demand can be greater in those locations even with the higher transportation cost. Thus, over some locations, the expected price gradient could be positive.
RECURSIVE ALGORITHMS FOR THE ELIMINATION OF REDUNDANT PATHS IN SPATIAL LAG OPERATORS*
Authors: Blommestein Hans J. , Koper Nick A. M.
Published: July 2006

ABSTRACT. Recursive algorithms for the elimination of redundant paths in spatial lag operators are introduced. It is shown that these algorithms have superior computational properties in comparison with the cumbersome procedure proposed by Ross and Harary (1952). A rigorous definition of spatial lag operators is given, while a number of mathematical results and properties are derived. Theoretical and empirical results regarding the performance of the proposed algorithms are presented.
THE EXCHANGEABILITY OF HEDONIC PROPERTY PRICE STUDIES*
Authors: Atkinson Scott E. , Crocker Thomas D.
Published: July 2006

ABSTRACT.Observations drawn from multiple markets are essential to the construction of indices of housing costs and to measures of demand for housing attributes. It is not evident when multiple markets exist or whether such markets exist for some attributes but not for others. We test for multiple markets by using Bayesian methods to assess the transferability (random exchangeability) of entire hedonic price expressions from one site and time to another, the transferability of hedonic price functions for particular attributes, and the degrees of similarity that hedonic price functions must have in order to be transferable. In our illustrations, price functions for structural housing attributes are generally transferable; prices for neighborhood attributes are not. Therefore, in our illustrations, the desired price indices and demand functions should be estimable for neighborhood attributes, but not for structural ones.
A DOUBLE‐ENTRY METHOD FOR THE CONSTRUCTION OF BI‐REGIONAL INPUT‐OUTPUT TABLES*
Authors: Boomsma Piet , Oosterhaven Jan
Published: July 2006

ABSTRACT. In The Netherlands, a strong tradition in the construction and updating of (inter)regional input‐output tables has been built up. The paper gives a brief overview of this Dutch experience and discusses the features of the by now more or less standardized double‐entry bi‐regional construction method (DEBRIOT). This method systematically adds sales and export coefficients to the usual construction procedures. Thus, it introduces consistency checks at the cell level of the input‐output table. Moreover, it offers a non‐survey technique to estimate a regional domestic sales table that is crucial to the double‐entry character of the method.
THE IMPACT OF ECONOMIC OPPORTUNITY, AMENITIES AND FISCAL FACTORS ON AGE‐SPECIFIC MIGRATION RATES
Authors: Clark David E. , Hunter William J.
Published: July 2006

ABSTRACT. Migration models have considered several different categories of determinants, including economic opportunities, amenities, and state and local fiscal factors. Migration has also been shown to depend on the individual's position in the life cycle. This paper represents a first attempt to integrate all three categories of determinants of migration into a life‐cycle framework. Empirical findings generated from a countrywide model of white male migration, over the period 1970 to 1980, reveal that all three types of determinants are important. Specifically, economic opportunities are most influential for males during their working years. Amenities are also found to follow a life‐cycle pattern with older migrants more attracted to amenable locations than their younger cohorts. Finally, state income and death taxes display life‐cycle effects; working males in their peak earning years are detracted by high income taxes while all migrants aged 55 to 69 avoid counties in states with high inheritance and estate taxes.
THE WELFARE ASPECTS OF SPATIAL PRICING POLICIES RECONSIDERED FOR A MONOPOLY CASE*
Authors: de Palma André , Liu Qin
Published: July 2006

ABSTRACT. We reexamine the price structures and their welfare implications in three pricing regimes (mill, uniform and discriminatory) for a monopoly. We show that spatial price discrimination could provide the highest social welfare and, when consumers tastes are heterogeneous enough, also the highest consumer surplus. The superiority of spatial price discrimination is partially due to the larger output produced and partially due to differential treatment for consumers with heterogeneous tastes.
LAND USE IN THE PRESENCE OF AN ATMOSPHERE EXTERNALITY, WITH AND WITHOUT CORRECTIVE TAXES*
Authors: Jones Donald W. , O'Neill Robert V.
Published: July 2006

ABSTRACT. Total cleared area in a von Thünen land‐use model drives an atmosphere externality which depresses agricultural productivity uniformly throughout the region. Exogenous events that encourage clearance and use of a larger cultivated area (output price or population increase) exacerbate the externality. Imposition of a simple, corrective tax on land rents does not reverse these patterns but does mitigate the increase in the externality and leaves cultivators with higher incomes than they would obtain without the tax. We examine an optimal tax on land rents, designed to maximize the social value of land rents in the region, and an output tax.
HOUSING SUBSIDIES AND URBAN HOUSEHOLD BEHAVIOR*
Authors: Turnbull Geoffrey K.
Published: July 2006

ABSTRACT. This paper examines how housing subsidies affect housing and location demands in a monocentric market, identifying the extent to which policies prompt targeted populations to congregate more or less intensely in the central city. Various subsidies are studied: rents based on ability to pay, lump‐sum housing aid, housing vouchers, and subsidies based on percentage of rent. The demand effects are seen to hinge critically upon whether or not subsidies are tied to binding consumption restrictions. Policy impacts are shown to be identical for both CBD employed and locally employed consumers targeted for the housing policies.
ALTERNATIVE EXPLANATIONS OF THE DEPENDENCE OF THE DENSITY OF CENTERS ON THE DENSITY OF POPULATION
Authors: Gusein‐Zade S. M.
Published: July 2006

ABSTRACT. The paper is devoted to modeling the relationship between the density of service centers and the density of population (or on the density of demand). Several models lead to an exponential function with the exponent equal to ⅔. For a number of real systems of centers, the power is considerably different from ⅔ (more often it is nearer to 1). I describe a series of models that explain this difference.
A COMPARATIVE ANALYSIS OF TIME SERIES APPROACHES TO MODELING INTERSECTORAL AND INTERCOUNTY EMPLOYMET LINKAGES IN RURAL REGIONAL LABOR MARKETS*
Authors: Fawson Christopher , Criddle Keith R.
Published: July 2006

ABSTRACT. The performance of five criteria for identifying significant interregional labor market linkages is compared. The criteria suggest differential model specifications based on the implicit tradeoff between parsimony and specification bias. Models were specified using: Akaike's final prediction error; Schwarz's Bayesian information criterion; an input‐output model; Aoki's time series algorithm; and a combined input‐outputi/time series approach. Models of the changes in monthly employment for twelve industries in six regions in northeastern Utah were specified using each criterion. Models based on Schwarz's criterion and the input‐output criterion were preferred to those based on other criteria.