高超声速风洞进气道流量系数测量精度影响因素研究

进气道是飞行器动力装置的重要组成部分,准确测量进气道流量系数是进气道风洞试验的重要内容。对来流马赫数Ma=4.5,5.0和6.0状态下皮托管进气道开展流量系数测量研究,通过对比理论值和实测值,获取各状态流量系数修正系数。试验结果表明,随着来流马赫数增加,进气道流量系数与理论值偏差较明显,并逐渐增大。超声速风洞试验通常认为测量截面总温与来流总温相等,通过对测量截面总温与来流总温偏差以及测量截面流场畸变情况的分析,判断测量偏差主要是由测量截面总温等于来流总温的假设导致的。在高超声速风洞试验中,由于模型壁面热交换的存在,测量截面总温低于来流总温,进气道流量系数测量时需要进行总温修正,以提高流量测量精度。      

军民深度协同对企业关键核心技术突破的影响

大国战略博弈与关键核心技术“卡脖子”背景下,推动军民深度协同对企业关键核心技术突破意义重大。以《关于经济建设和国防建设融合发展的意见》实施作为准自然实验,利用双重差分法考察军民深度协同对企业关键核心技术突破的影响及作用路径。结果发现,军民深度协同有助于企业关键核心技术突破。在进行平行趋势检验、安慰剂检验以及其它系列稳健性检验后,上述结论依然成立。机制检验发现,军民深度协同通过提升军地联合技术研发能力与军民两大市场资源配置效率以及缓解军民协同企业创新资源压力等“三轮驱动”机制,助力企业关键核心技术突破。进一步研究发现,军民深度协同可以助推军转民企业与民参军企业关键核心技术突破。结论对推进军民一体化发展和关键核心技术突破具有重要现实意义。     

The role of risk aversion in public goods dilemmas with environmental uncertainty: an experimental analysis

The purpose of this study is to extend earlier research on environmental uncertainty in public goods dilemmas. The present paper reports the results of an experiment designed to examine the effect of risk aversion on public goods provision. A von Neumann–Morgenstern utility function with constant coefficient of relative risk aversion is used to investigate the impact of risk attitudes within a threshold public goods environment. The outcome of the threshold public goods experiment shows that subjects are indifferent to the changes in environmental conditions. Additionally, the analysis indicates that risk aversion is a significant determinant of voluntary public goods contribution level.     

Behavioral Effects of Withholding Taxes on Labor Supply*

In most advanced economies, income tax collection uses third‐party withholding for wage income. Because withholding taxes do not necessarily reflect true effective taxes, these may give false signals of net‐of‐tax pay. We test labor supply responses to such misconceptions using laboratory experiments. Withholding taxes (and the resulting tax refunds) should be behaviorally neutral, but our results show that tax adjustments lead to effort adjustments, which suggests that withholding blurs tax incentives. While there is no statistically significant response in the overall sample, the participants in the subgroup who self‐assess to be motivated by monetary incentives (about half of the total sample) reduce their effort in response to withholding taxes and increase their effort after receiving tax refunds.     

How do electoral and voice accountability affect corruption? Experimental evidence from Egypt

How far does democracy decrease corruption? And which specific aspects of democracy help generate such effects? Corruption is famously one of the strongest obstacles to social and economic development. Whereas there has been extensive research identifying the causes of corruption, there is little experimental research on the impact of political institutions on corruption using designs that control for significant confounders. This paper uses a series of laboratory experiments conducted in 2013 Egypt in which a government official decides whether to spend tax revenues paid by subjects on a self-serving good or a good that benefits everyone equally. We have two experimental manipulations: (a) whether the official is electorally accountable to subjects or not; (b) whether subjects could send messages of protests to the official (and one another). We find evidence that electoral accountability does decrease the probability of the official choosing the self-serving good by 17% whereas voice accountability generates such outcome only in the authoritarian treatment (a reduction of corruption by 29%). We also find suggestive evidence that, in the authoritarian treatment, the likelihood of funding the self-serving good decreases by 27% when taxes paid by citizens fall short of the official’s threshold. Our contribution to the literature is two-fold: (a) we are able to single out the effect of specific democratic mechanisms on government corruption; (b) we test outcomes of democratic mechanisms on a traditionally understudied subject pool.     

The effect of endogenous timing on coordination under asymmetric information: An experimental study

This paper investigates the role of endogenous timing of decisions on coordination under asymmetric information. In the equilibrium of a global coordination game, where players choose the timing of their decision, a player who has sufficiently high beliefs about the state of the economy undertakes an investment without delay. This decision (potentially) triggers an investment by the other player whose beliefs would have led to inaction otherwise. Endogenous timing has two distinct effects on coordination: a learning effect (early decisions reveal information) and a complementarity effect (early decisions eliminate strategic uncertainty for late movers). The experiments that we conduct to test these theoretical results show that the learning effect of timing has more impact on the subjects' behavior than the complementarity effect. We also observe that subjects' welfare improves significantly under endogenous timing.     

Cooperation and discrimination within and across language borders: Evidence from children in a bilingual city

We present experimental evidence from a bilingual city in Northern Italy on whether the affiliation to a specific language group affects behavior in a prisoner׳s dilemma game and leads to discrimination. Running a framed field experiment with 828 six- to eleven-year old primary school children in the city of Meran, we find that cooperation generally increases with age, but that the gap between cooperation among in-group members and cooperation towards children speaking another language is considerable and develops with age. This gap is due to both in-group favoritism and language group discrimination. While the former is persistent across all age groups and both language groups and accounts for most of the discrimination observed, the latter only emerges in later years of primary school among children belonging to the German language group.     

The labor supply of fixed-wage workers: Estimates from a real effort experiment

Fixed-wage workers comprise the bulk of the labor force and yet little is known about how they respond to changes in their wage. Given recent interest in theories of reciprocity and intrinsic motivation and their implications for effort provision, the neoclassical prediction seems less obvious today. To better understand the motivation of these workers, I estimate their labor supply using a real effort experiment. Two results stand out. First, no one theory seems to fit the pooled data. On average, people work considerably harder than the minimum but they do not respond to changes in the wage. Second, pooling the data is deceptive because there seem to be distinct types with differing responses to the wage. Most workers can be classified as reciprocal or intrinsically motivated and, indeed, these types respond as theory would predict: reciprocators return wage gifts with increased effort and extrinsic incentives crowd out motivation for intrinsic workers.     

Chinese values and negotiation behaviour: A bargaining experiment

The importance of Chinese culture in cross-national negotiation has become conventional wisdom in international business research and practice. However, empirical work has not sufficiently established whether, how and under what conditions specific cultural values of the Chinese affect their negotiation decisions. This paper reports an experiment with a purpose-designed game task in which Chinese subjects divide a fixed gain over escalating stages. We find that concerns for face and harmony promote cooperative negotiation decisions while desire to win and risk seeking accentuate competitive ones. Values only predict behaviour in the critical, final stage of the bargaining process supporting a dynamic view of the effect of culture in negotiation.