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1.
In this paper, we explore the innovation growth of 200 mm and 300 mm silicon wafers from Taiwan. Using the historic data, we simulate the growth of the area of 200 mm and 300 mm silicon wafers manufactured in Taiwan by the competitive Lotka–Volterra model. The parameters in the Lotka–Volterra model estimated with the realistic data are obtained numerically. The dynamic growth of competitive relationship between 200 mm silicon wafers and 300 mm silicon wafers is then analyzed. To prove the performance of the model, we further compare the famous Bass model and the Lotka–Volterra model. We also perform the equilibrium analysis to determine the long-term stability state in the simulation trajectory. Our research exhibits that 200 mm silicon wafers and 300 mm silicon wafers show a prey–predator relationship under the assumption of natural competition in the global semiconductor market. From a managerial perspective, the coefficients in the Lotka–Volterra model of exponential growth, self-interaction and cross-interaction represent the strength of product attractiveness, niche capacity and interaction for two competition products. We also find that there exists a stable equilibrium state for 200 mm silicon wafers and 300 mm silicon wafers. The prey 200 mm generation does not disappear completely; it finally settles to a constant market alongside the predator 300 mm generation.  相似文献   

2.
In rapidly growing urban areas of developing countries, infrastructure has not been able to cope with population growth. Informal water businesses fulfill unmet water supply needs, yet little is understood about this sector. This paper presents data gathered from quantitative interviews with informal water business operators (n = 260) in Kisumu, Kenya, collected during the dry season. Sales volume, location, resource use, and cost were analyzed by using material flow accounting and spatial analysis tools. Estimates show that over 76% of the city's water is consumed by less than 10% of the population who have water piped into their dwellings. The remainder of the population relies on a combination of water sources, including water purchased directly from kiosks (1.5 million m3 per day) and delivered by hand-drawn water-carts (0.75 million m3 per day). Energy audits were performed to compare energy use among various water sources in the city. Water delivery by truck is the highest per cubic meter energy demand (35 MJ/m3), while the city's tap water has the highest energy use overall (21,000 MJ/day). We group kiosks by neighborhood and compare sales volume and cost with neighborhood-level population data. Contrary to popular belief, we do not find evidence of price gouging; the lowest prices are charged in the highest-demand low-income area. We also see that the informal sector is sensitive to demand, as the number of private boreholes that serve as community water collection points are much larger where demand is greatest.  相似文献   

3.
We investigate nine data series previously identified as containing bubbles using Bayesian Markov switching models.  Nearly all series appear to display strong regime switching that could possibly be induced by ‘bubble’ processes, but in each case the type of model that best describes each price differs substantively.  We pay particular attention to whether these series contain transient explosive roots, a feature which has been suggested to exist in several bubble formulations.  Bayesian model averaging is employed which allows us to average across a range of submodels, so that our empirical findings are not based on only one well performing model.  We show that explosive regimes may exist in many submodels, but only when the flexibility of the model is limited in other important respects.  In particular, when Markov switching models allow for switching levels of error variance, explosive root regimes occur in only a minority of the series.  相似文献   

4.
Conventional tests for the environmental Kuznets curve (EKC) hypothesis mostly apply a quadratic equation in modeling the non-linear relationship between environmental indices (such as air pollutants) and welfare measures (such as income per capita). If their inverted-U shaped pattern is empirically accepted with two significant regressors, the income per capita and its square transformation, the EKC hypothesis is supported. Using an OECD sample, this paper shows that the validity of testing the EKC hypothesis is sensitive to how we transform income non-linearly in sulfur and carbon EKC regressions. This paper carries out experiments on different powers of γ for transforming income non-linearly and concludes that only when 0 < γ < 1 and 1 < γ < 2 will the EKC regression demonstrate a testable non-linear cointegration relationship between the two air pollutants and income per capita. In the generalized EKC regressions estimated in this paper, although we find sulfur and carbon EKC patterns in the OECD sample, none of the EKC regressions using different γ is a cointegrating equation. This finding implies an inside critique to the EKC literature that failure of cointegration of the conventional EKC regression is not because of using the quadratic functional form, but because of the fundamentally spurious relationship between the trends of pollutants and income levels.  相似文献   

5.
Conventional tests for the environmental Kuznets curve (EKC) hypothesis mostly apply a quadratic equation in modeling the non-linear relationship between environmental indices (such as air pollutants) and welfare measures (such as income per capita). If their inverted-U shaped pattern is empirically accepted with two significant regressors, the income per capita and its square transformation, the EKC hypothesis is supported. Using an OECD sample, this paper shows that the validity of testing the EKC hypothesis is sensitive to how we transform income non-linearly in sulfur and carbon EKC regressions. This paper carries out experiments on different powers of γ for transforming income non-linearly and concludes that only when 0 < γ < 1 and 1 < γ < 2 will the EKC regression demonstrate a testable non-linear cointegration relationship between the two air pollutants and income per capita. In the generalized EKC regressions estimated in this paper, although we find sulfur and carbon EKC patterns in the OECD sample, none of the EKC regressions using different γ is a cointegrating equation. This finding implies an inside critique to the EKC literature that failure of cointegration of the conventional EKC regression is not because of using the quadratic functional form, but because of the fundamentally spurious relationship between the trends of pollutants and income levels.  相似文献   

6.
In March 1999, 31 million “shopping coupons” worth 20,000 yen each were distributed to Japanese families with children and to the elderly. The coupons expired after six months and could only be used within the recipient's local community. We use variation in the number of children across families and in the number of recipients across prefectures to measure the effect of the coupons on spending. We find that coupons had a positive effect on spending on semi-durables, but no effect on spending on nondurables or services. The marginal propensity to consume on semi-durables was 0.1–0.2 when the coupons were distributed in March. The results using regional variation provide stronger evidence that spending did not fall after the coupons had been redeemed.  相似文献   

7.
Economic growth results from the synthesis influence of various known or unknown and certain or uncertain factors. Mapping of the stimuli effects and the input and output estimates of artificial neural networks (ANN) are obtained via combinations of nonlinear functions. This approach offers the advantages of self-learning, self-organization, self-adaptation, and fault tolerance, as well as the potential for use in forecasting applications of economic growth. Furthermore, the ANN technology allows the use of multiple variables in both the input and output layers. This capability is very important for economic growth calculations because economic development is often a function of many influential variables. Herein, a forecasting system of economic growth with related application has been proposed, based on ANN. The results show that the Zhejiang proportions of tertiary industry in China for 1995, 1996, and 1997 were 32.305%, 32.174%, and 32.114%, respectively, and the comparative errors eann were 0.64%, − 0.08%, and − 0.27%, respectively, indicating that the forecast result of ANN was better than that of the GM(1.1) model. This method offered better performance and efficiency.  相似文献   

8.
Aiming at studying soil conservation function of alpine grassland in the Qinghai–Tibet Plateau, this paper simulated soil erosion changes under different degrees of human disturbance in a wind tunnel laboratory. Three types of grasslands were selected, which include alpine meadow (QH-1), alpine steppe meadow (QH-2) and alpine steppe (QH-3), and the soil erosion rate was taken as the index to measure soil conservation function. The experimental results show that the soil erosion rates of three grassland samples increase with wind velocity under different treatments but the increment of erosion rate varied greatly. Under original status, soil erosion rates are in turn QH-1 < QH-2 < QH-3, which indicates that the soil conservation services are QH-1 > QH-2 > QH-3. When the aboveground vegetation was cut, the soil erosion rate change of QH-1 is the same as that of QH-3 and compared with the original status both of them changed a little. And when the root system was destroyed the erosion rates range in turn as QH-1 < QH-2 < QH-3. So the data suggest that soil conservation service for the three types of grasslands should be QH-1 > QH-2 > QH-3. The economic values of soil conservation were estimated, which include the values of organic carbon fixation, nutrient retention and reducing soil disuse.  相似文献   

9.
This study evaluates the directional accuracy of production managers' forecasts by using a new market-timing test. By extending the directional analysis to the 4 × 4 case, this study investigates whether Japanese production managers' forecasts correctly predict turning points in production across different industries. This fills a gap in the literature that focused on predicting increase/decrease or acceleration/deceleration using directional analysis of the 2 × 2 case. It also illustrates its merit over the 2 × 2 case. This study shows that majority of the forecasts are not useful in predicting turning points in production; however, they are useful in predicting increase/decrease in production. Our findings suggest that the production managers' forecasts serve as early qualitative information of expansion and contraction on the Japanese economy and their accuracy does not differ by phases of business cycles.  相似文献   

10.
A two-equation integrated model is developed to capture bank profit and risk-avoidance decisions. Output is limited to customer loans. The profit function is based on output and selected inputs. Risk-avoidance (using the capitalization ratio) depends on micro and micro 1 macro interactive variables. The SUR method is used to test the hypothesis that the two functions are interdependent. Also, a single reduced-form equation is derived from the SUR model to analyze the volatility of the capitalization ratio. Five European countries and their banks for the period 1991–2001 are used to run the regressions and to test the hypothesis. The individual statistical results were generally consistent with similar results found in the literature. The Breusch–Pagan test of independence was rejected. A key finding from the volatility analysis suggests that bank profit rates are inversely related to the volatility of the banks' capitalization ratios as measured by their variances.  相似文献   

11.
Using a sample of monthly data from January 1996 to December 2012, we provide new evidence on the unidirectional Granger causality from real stock market returns to real economic activity in three Central and Eastern European countries: the Czech Republic, Hungary, and Poland. By employing the Granger causality tests of Cheung and Ng (1996) and Hong (2001), we show evidence of short-term (up to 6 months), medium-term (up to 12 months) and long-term (up to 24 months) causality for the Czech Republic and Hungary. In the case of Poland, only medium-term and long-term causality is found. Using rolling-correlation analysis, we find that although the growth–returns relationship is positive during the examined period, there is an apparent variability in the strength of this relationship that is particularly visible during the period of the financial crisis in the late 2000s. Consequently, we find that the predictive power of stock markets in the CEE-3 countries increases during periods of high market volatility and decreases during periods of economic recovery.  相似文献   

12.
The paper develops a new type of computable general equilibrium (CGE) model in which growth is fully endogenous, based on the increasing specialization of sector-specific capital varieties. The model is used to simulate the effects of carbon policies on consumption, welfare, and sectoral development in the long run. The benchmark scenario is calculated based on endogenous sector-specific gains from specialization, which carry over to the simulations of a carbon policy following the 2 °C target. Applying the model to the Swiss economy, we find that carbon policy leads to growth rates of knowledge intensive sectors that are higher than in the benchmark and that all the non-energy sectors show positive growth rates. Compared to a state in which climate change has no negative effect, consumption in 2050 is reduced by 4.5% and entails a moderate but not negligible welfare loss.  相似文献   

13.
In this paper, we assess future water demands for the agricultural (irrigation and livestock), energy (electricity generation, primary energy production and processing), industrial (manufacturing and mining), and municipal sectors, by incorporating water demands into a technologically-detailed global integrated assessment model of energy, agriculture, and climate change — the Global Change Assessment Model (GCAM). Base-year water demands – both gross withdrawals and net consumptive use – are assigned to specific modeled activities in a way that maximizes consistency between bottom-up estimates of water demand intensities of specific technologies and practices, and top-down regional and sectoral estimates of water use. The energy, industrial, and municipal sectors are represented in fourteen geopolitical regions, with the agricultural sector further disaggregated into as many as eighteen agro-ecological zones (AEZs) within each region. We assess future water demands representing six socioeconomic scenarios, with no constraints imposed by future water supplies. The scenarios observe increases in global water withdrawals from 3710 km3 year 1 in 2005 to 6195–8690 km3 year 1 in 2050, and to 4869–12,693 km3 year 1 in 2095. Comparing the projected total regional water withdrawals to the historical supply of renewable freshwater, the Middle East exhibits the highest levels of water scarcity throughout the century, followed by India; water scarcity increases over time in both of these regions. In contrast, water scarcity improves in some regions with large base-year electric sector withdrawals, such as the USA and Canada, due to capital stock turnover and the almost complete phase-out of once-through flow cooling systems. The scenarios indicate that: 1) water is likely a limiting factor in meeting future water demands, 2) many regions can be expected to increase reliance on non-renewable groundwater, water reuse, and desalinated water, but they also highlight an important role for development and deployment of water conservation technologies and practices.  相似文献   

14.
Sustainability as a concept has multiple disparate perspectives stemming from different related disciplines which either maintain ambiguous interpretations or concentrate on metrics pertaining to single aspects of a system. Given the embedded multi-dimensionality of sustainability, systemic approaches are needed that can cope with interactions of different dimensions. Past efforts for measuring sustainability holistically have taken an accounting approach based on the availability and efficiency of resource flows. However, an accounting approach fails to fully incorporate the intensive parameters pertaining to sustainability. An ecological information-based approach is a promising holistic measurement which incorporates both intensive and extensive dimensions of sustainability. This paper evaluates this approach by applying it to six economic resource trade flow networks: virtual water, oil, world commodity, OECD + BRIC commodity, OECD + BRIC foreign direct investment, and iron and steel. From the perspective of biomimicry, it appears that these networks can achieve higher levels of efficiency without weakening their robustness to resource delivery. The trends of measured efficiency and redundancy of the studied networks are demonstrated to be useful in reflecting long term changes while the trend in robustness levels were found to exhibit similar behavior to an ecosystem in its early phase of development.  相似文献   

15.
We propose a new methodology to study the stability of steady-state growth. Long-run GDP per capita can be characterized by: (1) the linear trend hypothesis, where there are no long-run changes in GDP levels or growth rates, (2) the level shift hypothesis, where there are long-run level shifts, but not changes in growth rates, and (3) the growth shift hypothesis, where there are long-run changes in both GDP levels and growth rates. We formally test these hypotheses using time series techniques with over 139 years of data. The results are not favorable to the hypothesis of constant steady-state growth. While we find evidence supporting the linear trend hypothesis for the United States and Canada and the level shift hypothesis for three additional OECD countries, the growth shift hypothesis is supported for seven OECD and four Asian countries. The results are not driven by transition dynamics.  相似文献   

16.
While China has emerged as one of the world's leading technological innovators, past studies have uncovered that technology centers have been overwhelmingly concentrated in Beijing and Shanghai. We take a step further to investigate whether this geographic concentration has persisted over time with nanotechnology-related patents. We apply the spatial analysis techniques and employ Gini's coefficient and global Moran's I. We additionally test the spatial patterns at four scales: the municipality, the county, the intra-metropolitan, and the distance-based.We find that while Beijing and Shanghai have remained the two dominant nanotechnology clusters, the Shanghai region, together with Jiangsu and Zhejiang, surpassed the traditionally productive Beijing–Tianjin region by 2007. We did not identify spatial autocorrelation at the province level, but at the county level, and at the scale between 20 km and 75 km. The intra-metropolitan analysis in Beijing and Shanghai further confirmed that the geographic concentration of nanotechnology is small, around 20 km. These results support the regional divergence theory and a small scale of technology diffusion, as well as the possibility of continually increasing inequality in China and its technology development.  相似文献   

17.
We examine the relationship between two inflation indices, consumer price index (CPI) and producer price index (PPI) for Mexico, a case study country which has successfully implemented inflation targeting after the economic crisis and high inflationary situation in 1995. Since the causality running from PPI to CPI exemplifies the cost push nature of inflation and the opposite is the indicator of demand pull inflation, this analysis could provide significant policy implications. We contribute to the literature by decomposing the time–frequency relationship between CPI and PPI through continuous wavelet approach. Our results indicate a bidirectional relationship between CPI and PPI. In short periods (1 to 7 months scale) CPI is leading PPI, while for longer periods (8 to 32 months scale) PPI is the leading variable.  相似文献   

18.
Giving up an independent monetary policy and a flexible exchange rate are the key aspects of joining a monetary union. In this paper we analyse how joining the euro area would have affected the Polish business cycle during the recent financial crisis. To this end we construct a small open economy DSGE model and estimate it for Poland and the euro area. Then we run a counterfactual simulation, assuming Poland's euro area accession in 1q2007. The results are striking — volatilities of GDP and inflation increase substantially. In particular, had Poland adopted the euro, GDP growth would have oscillated between − 6% and + 9% (− 9% to + 11% under more extreme assumptions) instead of between 1% and 7%. We conclude that during the analysed period independent monetary policy and, in particular, the flexible exchange rate played an important stabilizing role for the Polish economy.  相似文献   

19.
Deforestation and forest degradation are estimated to account for between 12% and 20% of annual greenhouse gas emissions and in the 1990s (largely in the developing world) released about 5.8 Gt per year, which was bigger than all forms of transport combined. The idea behind REDD + is that payments for sequestering carbon can tip the economic balance away from loss of forests and in the process yield climate benefits. Recent analysis has suggested that developing country carbon sequestration can effectively compete with other climate investments as part of a cost effective climate policy.This paper focuses on opportunities and complications associated with bringing community-controlled forests into REDD +. About 25% of developing country forests are community controlled and therefore it is difficult to envision a successful REDD + without coming to terms with community controlled forests. It is widely agreed that REDD + offers opportunities to bring value to developing country forests, but there are also concerns driven by worries related to insecure and poorly defined community forest tenure, informed by often long histories of government unwillingness to meaningfully devolve to communities. Further, communities are complicated systems and it is therefore also of concern that REDD + could destabilize existing well-functioning community forestry systems.  相似文献   

20.
Dense, expensive, litigious, and highly regulated, Manhattan typifies coastal US housing markets. Manhattan has lost share of US residential construction over the last 45 years. Some attribute this trend to tightening local regulation, but the decline of public housing construction and the decreasing national share of construction that is multifamily jointly explain away Manhattan's decline. Across US counties, negative correlations between supply growth and both coastal status and regulations disappear conditional on population density.  相似文献   

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