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Long-term Growth Rate (long-term + growth_rate)

Distribution by Scientific Domains
Life Sciences83%

Selected Abstracts

Fiscal Transfers and Distributive Conflict in a Simple Endogenous Growth Model with Unemployment

GERMAN ECONOMIC REVIEW, Issue 1 2007
Luigi Bonatti
Capital,labor conflict; endogenous growth; politico-economic models; tax burden; welfare reforms Abstract. In the simplified formal treatment proposed in this paper, a decrease in a policy parameter , the ratio of total tax revenues to GDP , can monotonically increase long-term growth rate and may lead to a higher employment level. This notwithstanding, the paper shows that the redistributive implications of such a decrease may induce the wage earners to oppose it. As a consequence, policy-makers reflecting social preferences may undertake redistributive transfers generating persistent unemployment and lowering growth even if commitment technologies allowing them to follow preannounced tax policies were feasible. [source]

Dynamics of an age-structured population drawn from a random numbers table

AUSTRAL ECOLOGY, Issue 4 2000
Bertram G. Murray JR
Abstract I constructed age-structured populations by drawing numbers from a random numbers table, the constraints being that within a cohort each number be smaller than the preceding number (indicating that some individuals died between one year and the next) and that the first two-digit number following 00 or 01 ending one cohort's life be the number born into the next cohort. Populations constructed in this way showed prolonged existence with total population numbers fluctuating about a mean size and with long-term growth rate (r) , 0. The populations' birth rates and growth rates and the females' per capita fecundity decreased significantly with population size, whereas the death rates showed no significant relationship to population size. These results indicate that age-structured populations can persist for long periods of time with long-term growth rates of zero in the absence of negative-feedback loops between a population's present or prior density and its birth rate, growth rate, and fecundity, contrary to the assumption of density-dependent regulation hypotheses. Thus, a long-term growth rate of zero found in natural populations need not indicate that a population's numbers are regulated by density-dependent factors. [source]

Dynamics of an age-structured population drawn from a random numbers table

AUSTRAL ECOLOGY, Issue 4 2000
BERTRAM G. MURRAY JR
Abstract I constructed age-structured populations by drawing numbers from a random numbers table, the constraints being that within a cohort each number be smaller than the preceding number (indicating that some individuals died between one year and the next) and that the first two-digit number following 00 or 01 ending one cohort's life be the number born into the next cohort. Populations constructed in this way showed prolonged existence with total population numbers fluctuating about a mean size and with long-term growth rate (r) , 0. The populations' birth rates and growth rates and the females' per capita fecundity decreased significantly with population size, whereas the death rates showed no significant relationship to population size. These results indicate that age-structured populations can persist for long periods of time with long-term growth rates of zero in the absence of negative-feedback loops between a population's present or prior density and its birth rate, growth rate, and fecundity, contrary to the assumption of density-dependent regulation hypotheses. Thus, a long-term growth rate of zero found in natural populations need not indicate that a population's numbers are regulated by density-dependent factors. [source]

Allometry, growth and population regulation of the desert shrub Larrea tridentata

FUNCTIONAL ECOLOGY, Issue 2 2008
A. P. Allen
Summary 1Quantifying the effects of individual- and population-level processes on plant-community structure is of fundamental importance for understanding how biota contribute to the flux, storage and turnover of matter and energy in ecosystems. 2Here we synthesize plant-allometry theory with empirical data to evaluate the roles of individual metabolism and competition in structuring populations of the creosote Larrea tridentata, a dominant shrub in deserts of southwestern North America. 3At the individual level, creosote data support theoretical predictions with regard to the size dependence of total leaf mass, short-term growth rates of leaves and long-term growth rates of entire plants. Data also support the prediction that root,shoot biomass allocation is independent of plant size. 4At the population level, size,abundance relationships within creosote stands deviate strongly from patterns observed for steady-state closed-canopy forests due to episodic recruitment events. This finding highlights that carbon storage and turnover in water-limited ecosystems can be inherently less predictable than in mesic environments due to pronounced environmental forcing on demographic variables. 5Nevertheless, broad-scale comparative analyses across ecosystems indicate that the relationship of total abundance to average size for creosote populations adhere to the thinning rule observed and predicted by allometry theory. This finding indicates that primary production in water-limited ecosystems can be independent of standing biomass due to competition among plants for resources. 6Our synthesis of theory with empirical data quantifies the primary roles of individual-level metabolism and competition in controlling the dynamics of matter and energy in water-limited ecosystems. [source]

Dynamics of an age-structured population drawn from a random numbers table

AUSTRAL ECOLOGY, Issue 4 2000
Bertram G. Murray JR
Abstract I constructed age-structured populations by drawing numbers from a random numbers table, the constraints being that within a cohort each number be smaller than the preceding number (indicating that some individuals died between one year and the next) and that the first two-digit number following 00 or 01 ending one cohort's life be the number born into the next cohort. Populations constructed in this way showed prolonged existence with total population numbers fluctuating about a mean size and with long-term growth rate (r) , 0. The populations' birth rates and growth rates and the females' per capita fecundity decreased significantly with population size, whereas the death rates showed no significant relationship to population size. These results indicate that age-structured populations can persist for long periods of time with long-term growth rates of zero in the absence of negative-feedback loops between a population's present or prior density and its birth rate, growth rate, and fecundity, contrary to the assumption of density-dependent regulation hypotheses. Thus, a long-term growth rate of zero found in natural populations need not indicate that a population's numbers are regulated by density-dependent factors. [source]

Dynamics of an age-structured population drawn from a random numbers table

AUSTRAL ECOLOGY, Issue 4 2000
BERTRAM G. MURRAY JR
Abstract I constructed age-structured populations by drawing numbers from a random numbers table, the constraints being that within a cohort each number be smaller than the preceding number (indicating that some individuals died between one year and the next) and that the first two-digit number following 00 or 01 ending one cohort's life be the number born into the next cohort. Populations constructed in this way showed prolonged existence with total population numbers fluctuating about a mean size and with long-term growth rate (r) , 0. The populations' birth rates and growth rates and the females' per capita fecundity decreased significantly with population size, whereas the death rates showed no significant relationship to population size. These results indicate that age-structured populations can persist for long periods of time with long-term growth rates of zero in the absence of negative-feedback loops between a population's present or prior density and its birth rate, growth rate, and fecundity, contrary to the assumption of density-dependent regulation hypotheses. Thus, a long-term growth rate of zero found in natural populations need not indicate that a population's numbers are regulated by density-dependent factors. [source]