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1.
In an inventory model with exogenous sales, FIFO and LIFO criteria are formalized and compared with national account estimates for intermediate and finished good products. The model is simulated by utilizing manufacturing input and output prices for Italy (1970–88). LIFO and national account estimates of inventory are usually close and also imply reliable measures of output level and changes which can be shown by solving the quantity model. Conversely, FIFO exhibits larger profits and leads in real terms to unsatisfactory estimates of output changes.  相似文献   
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In questo lavoro si introducono cinque nuove classi di funzioni concave generalizzate; di esse si studiano le proprietà e le interrelazioni con le classi più note in letteratura. Più precisamente, dopo aver evidenziato che le nuove classi sono distinte tra loro e da quelle già note in letteratura, se ne analizzano organicamente le differenze e si studia il loro comportamento dapprima in ipotesi di semicontinuità superiore e poi in ipotesi di continuità. Nel lavoro si dimostra inoltre il mantenimento di alcune proprietà strutturali come pure la conservazione delle principali proprietà relative all'ottimizzazione.
Summary In this paper five new classes of generalized-concave functions are introduced and studied. In particular, it is firstly pointed out that the new classes are different from the known ones, then their relationships are stressed both in general and under hypothesis of upper semicontinuity and continuity.Also some properties about optimization and functions transformation are provided.
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The expression “the bell curve” designs both a kind of statistical distribution and the title of a famous and controversial book by Herrnstein and Murray. The first is so attractive that the second refers to it to give more credibility to its questionable theories on intelligence. The point is that, during the 20th century, the bell curve has assumed a more and more important role in psychological research and practice and have become both a reality and a myth. In the first case (reality) we can assist to appropriate applications of a real useful statistical concept. In the second (myth) we can have two kinds of attitudes: one attitude is typical of those researchers who search for normality in all their data and variables, just as Parsifal used to search for the Holy Graal (we call this “the Parsifal attitude”); the other is typical of those researchers who give normality for granted and act as if it were a Platonic Idea (we call this “the Plato attitude”). The article discusses the role of the normal distribution in psychological research and practice and shows how it can be dangerous to treat the bell curve as a God or an Idol.  相似文献   
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Contingent valuation studies are often characterized by a considerable number of protest responses, which may cause selectivity bias on the final estimates for WTP. Sample selection models can detect and – if necessary – correct selectivity bias. In economic applications where the relevant dependent variable is continuous, sample selection models are generally estimated using Heckman's 2-step method rather than the FIML estimator. Either method has its own drawback: computational complexity for the FIML method, susceptibility to collinearity problems for the 2-step method. Using data on valuation of forest resources for recreational use, we analyse the performance of the two estimators. In this application, given the presence of some collinearity, the FIML is preferred to the 2-step method. A procedure is outlined to deal with selectivity problems in similar settings.  相似文献   
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Entry costs vary dramatically across countries. To assess their impact on cross-country differences in output and TFP, we construct a model with endogenous entry and operation decisions by firms. We calibrate the model to match the U.S. distribution of employment and firms by size. Higher entry costs lead to greater misallocation of productive factors and lower TFP and output. In the model, countries in the lowest decile of the entry costs distribution have 1.32 to 1.45 times higher TFP and 1.52 to 1.75 times higher output per worker than countries in the highest decile. As in the data, higher entry costs are associated with lower entry rates and business density.  相似文献   
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Dolphin-watching tourism is growing globally. In developing countries, the typically low environmental awareness of operators and poorly enforced or non-existent regulations exacerbate risks to wildlife. Ecological indicators like behavioural responses are useful to assess wildlife tourism, but obtaining such data is slow and expensive. We modified the Driver–Pressure–State–Impact–Response (DPSIR) framework to rapidly assess the risk of dolphin-watching tourism harming, displacing or causing local extinction to dolphin populations, using human dimension data to complement limited ecological data. We assessed industries at seven dolphin-watching sites in six countries in Asia: Cambodia, India, Indonesia, Malaysia, Thailand, and the Philippines. All sites have reached or almost reached financial saturation except Cambodia and Malaysia. We find high risk to dolphins at the sites in India and Indonesia and intermediate risk at the site in Cambodia. Pending more ecological data, the risk at Thailand, the Philippines, and Malaysian sites might be low. Our analysis also indicates site-specific conservation recommendations for Driver, Pressure and Response. We suggest that the DPSIR framework is useful to assess the risk of a wildlife watching industry, even when the impact is uncertain due to insufficient ecological data.  相似文献   
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We review the basic principles for the evaluation of design efficiency in discrete choice modelling with a focus on efficiency of WTP estimates from the multinomial logit model. The discussion is developed under the realistic assumption that researchers can plausibly define a prior belief on the range of values for the utility coefficients. D‐, A‐, B‐, S‐ and C‐errors are compared as measures of design performance in applied studies and their rationale is discussed. An empirical example based on the generation and comparison of fifteen separate designs from a common set of assumptions illustrates the relevant considerations to the context of non‐market valuation, with particular emphasis placed on C‐efficiency. Conclusions are drawn for the practice of reporting in non‐market valuation and for future work on design research.  相似文献   
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