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991.
Anders Böhlmark Erik Grönqvist Jonas Vlachos 《The Scandinavian journal of economics》2016,118(4):912-940
We estimate the impact of individual principals on school outcomes by using panel data that allow us to track principals over time. We find that individual principals have a substantive impact on school policies, working conditions, and student outcomes. In particular, students who attend a school that has a one standard deviation better principal improve their achievement by between 0.05 and 0.1 standard deviations. Despite rich background information on principals, it is difficult to characterize successful management, suggesting that innate skills are central. We find that the scope for discretion is larger among voucher schools and in areas with school competition. 相似文献
992.
L. H. Chuang B. G. Verheggen M. Charokopou D. Gibson S. Grandy B. Kartman 《Journal of medical economics》2016,19(12):1127-1134
Objective: To assess the cost-effectiveness of exenatide 2?mg once-weekly (EQW) compared to dulaglutide 1.5?mg QW, liraglutide 1.2?mg and 1.8?mg once-daily (QD), and lixisenatide 20?μg QD for the treatment of adult patients with type 2 diabetes mellitus (T2DM) not adequately controlled on metformin.Methods: The Cardiff Diabetes Model was applied to evaluate cost-effectiveness, with treatment effects sourced from a network meta-analysis. Quality-adjusted life years (QALYs) were calculated with health-state utilities applied to T2DM-related complications, weight changes, hypoglycemia, and nausea. Costs (GBP £) included drug treatment, T2DM-related complications, severe hypoglycemia, nausea, and treatment discontinuation due to adverse events. A 40-year time horizon was used.Results: In all base-case comparisons, EQW was associated with a QALY gain per patient; 0.046 vs dulaglutide 1.5?mg; 0.102 vs liraglutide 1.2?mg; 0.043 vs liraglutide 1.8?mg; and 0.074 vs lixisenatide 20?μg. Cost per patient was lower for EQW than for liraglutide 1.8?mg (?£2,085); therefore, EQW dominated liraglutide 1.8?mg. The cost difference per patient between EQW and dulaglutide 1.5?mg, EQW and liraglutide 1.2?mg, and EQW and lixisenatide 20?μg was £27, £103, and £738, respectively. Cost per QALY gained with EQW vs dulaglutide 1.5?mg, EQW vs liraglutide 1.2?mg, and EQW vs lixisenatide 20?μg was £596, £1,004, and £10,002, respectively. In the probabilistic sensitivity analysis, the probability that EQW is cost-effective ranged from 76–99%.Conclusion: Results suggest that exenatide 2?mg once-weekly is cost-effective over a lifetime horizon compared to dulaglutide 1.5?mg QW, liraglutide 1.2?mg QD, liraglutide 1.8?mg QD, and lixisenatide 20?μg QD for the treatment of T2DM in adults not adequately controlled on metformin alone. 相似文献
993.
994.
We analyze optimal merger policy in R&D-intensive industries with product innovation aiming to improve the quality of products. Our results suggest that a permissive merger policy is rarely optimal in high-tech industries when the antitrust authority considers a welfare standard that balances the impact of mergers on consumers’ surplus and firms’ profits. In particular, relative to a benchmark where the effects from R&D are absent, we show that the optimal merger policy should not be substantially more permissive in the presence of those effects from R&D. 相似文献
995.
This paper considers the assignment of tradable permits—representing property rights of an environmental good—to community members who are harmed by pollution generated by firms. These community members can in turn sell permits to polluters according to their personal preferences. For a special case with a sole household, market transactions between the household and polluters achieve an efficient pollution level. However, for a group of households, the decentralized market solution fails to yield social efficiency because of competitive consumption of the environmental goods. We design a revenue-sharing mechanism akin to unitization, under which market transactions also achieve efficient resource allocation. Importantly, in some cases, efficiency can be achieved even when regulators are ignorant of the private valuation of the environmental good. 相似文献
996.
Smart devices such as smartphones and tablets are used extensively in public spaces for the transmission and reception of content in the form of text, photos and streaming videos. Since the bandwidth provided for wireless access is limited in public areas, it becomes an issue for users to gain access to the bandwidth they need at the right times. While an omniscient controller could assign bandwidth to each device on the basis of their needs and overall availability, imperfect information about the instantaneous state of the wifi access patterns and needs of users make for a very inefficient allocation of such bandwidth. This paper provides a solution for bandwidth allocation by creating a market among users of smart devices so that they can bid for extra bandwidth when they need it and sell it when they don’t. They do so by using a virtual currency that is conserved so that each device owner maximizes his own utility. This utility function is composed of both the benefit accrued from accessing bandwidth and the loss of the currency incurred in bidding for such bandwidth. Extensive simulations show that this market-based method outperforms an omniscient model when demand is uncertain, while minimizing bandwidth consumption. 相似文献
997.
James Alm 《Journal of economic surveys》2015,29(2):230-262
Improved urban infrastructure is widely believed to be essential in facilitating economic growth and in improving the lives of urban dwellers, both in developed and in developing countries. This paper focuses on several dimensions of urban infrastructure finance: finance for major infrastructure improvements in major economic centers, finance for expansion of basic municipal services in secondary cities and towns, and intergovernmental systems for financing investments with impacts beyond jurisdictional limits. It reviews what is “known” about current practices in these areas, using international evidence and case studies and summarizing international best practices. It also indicates areas in which knowledge gaps remain. Despite these “unknowns,” there are avenues by which our understanding of infrastructure schemes can be enhanced, and some suggestions for a research agenda on financing urban infrastructure are offered in the concluding section. 相似文献
998.
This paper examines the wide-spread practice where data envelopment analysis (DEA) efficiency estimates are regressed on some
environmental variables in a second-stage analysis. In the literature, only two statistical models have been proposed in which
second-stage regressions are well-defined and meaningful. In the model considered by Simar and Wilson (J Prod Anal 13:49–78,
2007), truncated regression provides consistent estimation in the second stage, where as in the model proposed by Banker and Natarajan
(Oper Res 56: 48–58, 2008a), ordinary least squares (OLS) provides consistent estimation. This paper examines, compares, and contrasts the very different
assumptions underlying these two models, and makes clear that second-stage OLS estimation is consistent only under very peculiar
and unusual assumptions on the data-generating process that limit its applicability. In addition, we show that in either case,
bootstrap methods provide the only feasible means for inference in the second stage. We also comment on ad hoc specifications
of second-stage regression equations that ignore the part of the data-generating process that yields data used to obtain the
initial DEA estimates. 相似文献
999.
1000.
In this paper we propose two new indicators of de facto constitutional constraints. The indicators are based on the presence or the absence of easily observable political events. This makes the proposed measures relatively objective and easy to verify relative to the most widely used indicators of de jure and de facto constitutions. This paper describes the indicators and demonstrates their usefulness for research on economic development. 相似文献