跳出地产看地产——试论滨海新区房地产的宏观走势

滨海新区的开发开放正式纳入国家战略已有一年,在此前后,滨海新区的房地产开发热已持续近两年.静观这两年的事态变化,开发者已由最初的喧嚣、癫狂而趋于理性,置业者和投资者浮躁的功利心态也逐步冷却.显然,坊间追捧和媒体热炒的房地产开发"盛世"并未如期而至;一些先行者创造的个案营销神话,似乎也未再现,惟一的奇迹,就是滨海的房价一再拉高,已经与中心城区比肩.滨海新区的房地产到底出现了什么问题?原因何在?需要有一个客观的诊断和解答.     

Assessing the effects of land use and land cover patterns on thermal conditions using landscape metrics in city of Indianapolis,United States

Direct applications of remote sensing thermal infrared (TIR) data in landscape ecological research are rare due to limitations in the sensors, calibration, and difficulty in interpretation. Currently there is a general lack of methodology for examining the relationship between land surface temperatures (LST) derived from TIR data and landscape patterns extracted from optical sensors. A separation of landscapes into values directly related to their scale and signature is a key step. In this study, a Landsat ETM+ image of Indianapolis, Unites States, acquired on June 22, 2000, was spectrally unmixed (using spectral mixture analysis, SMA) into fraction endmembers of green vegetation, soil, high albedo, and low albedo. Impervious surface was then computed from the high and low albedo images. A hybrid classification procedure was developed to classify the fraction images into seven land use and land cover (LULC) classes. Using the fractional images, the landscape composition and pattern were examined. Next, pixel-based LST measurements were correlated with the landscape fractional components to investigate LULC based relationships between LST and impervious surface and green vegetation fractions. An examination of the relationship between the LULC and LST maps with landscape metrics was finally conducted to deepen understanding of their interactions. Results indicate that SMA-derived fraction images were effective for quantifying the urban morphology and for providing reliable measurements of biophysical variables. LST was found to be positively correlated with impervious surface fraction but negatively correlated with green vegetation fraction. Each temperature zone was associated with a dominant LULC category. Further research should be directed to the theoretical and applied implications of describing such relationships between LULC patterns and urban thermal conditions.

Bayesian t-tests for correlations and partial correlations

In this paper, we develop Bayes factor based testing procedures for the presence of a correlation or a partial correlation. The proposed Bayesian tests are obtained by restricting the class of the alternative hypotheses to maximize the probability of rejecting the null hypothesis when the Bayes factor is larger than a specified threshold. It turns out that they depend simply on the frequentist t-statistics with the associated critical values and can thus be easily calculated by using a spreadsheet in Excel and in fact by just adding one more step after one has performed the frequentist correlation tests. In addition, they are able to yield an identical decision with the frequentist paradigm, provided that the evidence threshold of the Bayesian tests is determined by the significance level of the frequentist paradigm. We illustrate the performance of the proposed procedures through simulated and real-data examples.     

Opting out of workers’ compensation: Non-subscription in Texas and its effects

Journal of Risk and Uncertainty - Texas is the only state that does not mandate that employers carry workers’ compensation (WC) insurance coverage. In place of traditional WC, companies can...     

Transparency and Resource Allocation of Grassroots Nonprofits in China

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - Organizational transparency has become a prominent concern for the nonprofit sector as it expands globally. Transparency...     

ON EQUILIBRIUM PLAYER ORDERING IN DYNAMIC TEAM CONTESTS

We study equilibrium player ordering in a dynamic all-pay contest between two teams. The contest lasts two periods, and each team consists of two players who perform in different periods on behalf of their teams. The team with the higher aggregate output wins the prize, which is a public good to its players. Each team has one stronger player and one weaker player, and the two teams can differ in their values of the prize. The teams maximize their winning odds by strategically assigning their players to different periods. We find that when the intrateam heterogeneity in player ability is not excessive, the teams would allocate their stronger players to the late positions as the “anchormen.” When both the intrateam ability gap and interteam heterogeneity in teams' values become excessively large, the team with high value always places its stronger player in the early position, who will place a large bid to preempt late competition. (JEL C7, D7, D8)     

居民养老保险:参保主体、筹资与待遇水平

本文从参保结构、筹资水平和待遇水平等3个方面对城乡居民养老保险制度进行了分析。研究发现,在参保结构方面,伴随着城镇化率的提高,居民养老保险参保人数的相对比例在下降;在筹资水平方面,个人缴费水平过低,其主要原因是财政补贴资金激励性不足,从而需要在进一步提高财政补贴的同时,优化补贴结构,提高对个人缴费的激励作用;在待遇方面,居民养老金总体水平较低、但增长幅度较大,与职工待遇相比,替代率的差距要远远小于绝对额的差距。     

Robust inference for estimating equations with nonignorably missing data based on SIR algorithm

Nonresponse is a very common phenomenon in survey sampling. Nonignorable nonresponse – that is, a response mechanism that depends on the values of the variable having nonresponse – is the most difficult type of nonresponse to handle. This article develops a robust estimation approach to estimating equations (EEs) by incorporating the modelling of nonignorably missing data, the generalized method of moments (GMM) method and the imputation of EEs via the observed data rather than the imputed missing values when some responses are subject to nonignorably missingness. Based on a particular semiparametric logistic model for nonignorable missing response, this paper proposes the modified EEs to calculate the conditional expectation under nonignorably missing data. We can apply the GMM to infer the parameters. The advantage of our method is that it replaces the non-parametric kernel-smoothing with a parametric sampling importance resampling (SIR) procedure to avoid nonparametric kernel-smoothing problems with high dimensional covariates. The proposed method is shown to be more robust than some current approaches by the simulations.     

A misspecification test for the higher order co-moments of the factor model

The traditional estimation of higher order co-moments of non-normal random variables by the sample analog of the expectation faces a curse of dimensionality, as the number of parameters increases steeply when the dimension increases. Imposing a factor structure on the process solves this problem; however, it leads to the challenging task of selecting an appropriate factor model. This paper contributes by proposing a test that exploits the following feature: when the factor model is correctly specified, the higher order co-moments of the unexplained return variation are sparse. It recommends a general to specific approach for selecting the factor model by choosing the most parsimonious specification for which the sparsity assumption is satisfied. This approach uses a Wald or Gumbel test statistic for testing the joint statistical significance of the co-moments that are zero when the factor model is correctly specified. The asymptotic distribution of the test is derived. An extensive simulation study confirms the good finite sample properties of the approach. This paper illustrates the practical usefulness of factor selection on daily returns of random subsets of S&P 100 constituents.     

Lighting Effects on Older Adults’ Visual and Nonvisual Performance: A Systematic Review

Lighting plays an important role in daily life: It helps people perform daily activities independently and safely, and also benefits their health. This study assesses the research evidence of lighting’s impacts on older adults in four domains: (a) performance of activities of daily living and instrumental activities of daily living; (b) circadian rhythm; (c) fall prevention and postural stability; and (d) sleep quality. A comprehensive review of lighting studies on older adults’ visual and nonvisual performance was conducted using a modified PRISMA systematic review process. For the first domain, some older adults had difficulty in using the toilet, preparing meals, and doing laundry under lower illuminance. For the second domain, brighter and bluish lighting improved older adults’ circadian rhythm. For the third domain, low-intensity LED lighting affixed on door frames can help older adults maintain postural stability and prevent falling during nighttime movement. Finally, some studies concluded that receiving outdoor daylight during exercise was beneficial to older adults’ sleep quality. This study provides several methodological, theoretical, and collaborative suggestions for developing a more conclusive evidence base for lighting standards and strategies for older adults.