Pareto-Efficient Solutions for Shared Public Good Provision: Nash Bargaining versus Exchange-Matching-Lindahl

We compare two cooperation mechanisms for consumer/producers of a public good: the Nash Bargaining Solution (NBS) and the Exchange-Matching-Lindahl (EML) solution, where each agent specifies her demand for and supply of the public good according to her personal exchange rate. Both mechanisms are Pareto-efficient. EML is equivalent to matching. In our specific model with linear or quadratic benefits and quadratic costs, EML and NBS are equivalent when there are two agents. With more than two agents, the high-benefit/low-cost agents are better off under EML. We also analyze outsourcing, where agent i can pay agent j to produce the amount that agent i promised to contribute. In our specific model, payments from high-cost to low-cost agents (and from high-benefit to low-benefit agents) are (usually) lower in EML than in NBS.     

Adoption and Ex-post Impacts of Improved Cowpea Varieties on Productivity and Net Returns in Nigeria

Cowpea covers the largest area of any grain legume in Africa and is especially important in West Africa where Nigeria and Niger alone account for over 75% of the total cowpea production in the world. Despite successes of international and national cowpea improvement research in the development and release of several improved varieties, there is limited empirical evidence of adoption and ex-post impacts of improved cowpea. Using a nationally representative survey data from a sample of 1,525 cowpea-growing households in northern Nigeria cultivating over 2,500 cowpea plots, we assess the adoption and impacts of improved cowpea varieties on cowpea yields, net returns and production costs. We apply a control function approach and propensity score matching models to estimate the causal effects of adoption of improved cowpea varieties . Our results show that 38% of the cowpea plots were planted with improved varieties, and cowpea yields, net returns and production costs increase significantly with the adoption of improved cowpea varieties. Adoption of improved cowpea varieties is associated on average with 26% yield gains, 61% increase in net returns and 14% increase in production costs. We also show that farmers who have a lower propensity to adopt improved cowpea varieties also face higher costs of production.     

Consumption Responses to a Large Shock to Financial Wealth: Evidence from Italy

We estimate marginal propensities to consume from wealth shocks. We exploit large asset-price shocks in 2007–2008 and household-level panel data to implement instrumental variables. A fall of one euro in risky financial wealth resulted in cuts to annual total (non-durable) consumption of 8.5–9 (5.5–5.7) cents, with small effects on food spending. Effects seem stronger for lower-wealth or indebted households, but significant responses from wealthier households and those without mortgages are important for our baseline results. Counterfactuals indicate financial-wealth effects were relatively important for consumption falls in Italy in 2007–2008. The estimated effects are consistent with a simulated life-cycle model capturing the wealth shock.     

Evaluating the performance of a predictive modeling approach to identifying members at high-risk of hospitalization

Abstract

Aims: To evaluate the risk-of-hospitalization (ROH) models developed at Blue Cross Blue Shield of Louisiana (BCBSLA) and compare this approach to the DxCG risk-score algorithms utilized by many health plans.

Materials and Methods: Time zero for this study was December 31, 2016. BCBSLA members were eligible for study inclusion if they were fully insured; aged 80?years or younger; and had continuous enrollment starting on or before June 1, 2016, through time zero. Up to 2?years of historical claims data from time zero per patient was included for model development. Members were excluded if they had cancer, renal failure, or were admitted for hospice. The Blue Cross ROH models were developed using (1) regularized logistic regression and (2) random decision forests (a tree ensemble learning classification method). All models were generated using Scikit-learn: Machine Learning in Python. Prognostic capabilities of DxCG risk-score algorithms were compared to those of the Blue Cross models.

Results: When stratifying by the top 0.1% of members with the highest ROH, the Blue Cross logistic regression model had the highest area under the receiving operator characteristics curve (0.862) based on the result of 10-fold cross-validation. The Blue Cross random decision forests model had the highest positive predictive value (49.0%) and positive likelihood ratio (61.4), but sensitivity, specificity, negative predictive values, and negative likelihood ratios were similar across all four models.

Limitations: The Blue Cross ROH models were developed and evaluated using BCBSLA data, and predictive power may fluctuate if applied to other databases.

Conclusions: The predictability of the Blue Cross models show how member-specific, regional data can be used to accurately identify patients with a high ROH, which may allow healthcare workers to intervene earlier and subsequently reduce the healthcare burden for patients and providers.     

散粮流程接卸皮带机产能提速升级改造工程的推广与应用

西5#泊位是公司粮食接卸的主力泊位,利用率高达90%以上,双线卸船效率3 000 t·h-1,临港企业系统设计能力800 t·h-1左右,港企接卸能力不匹配成为影响卸船效率的一大瓶颈。根据生产需要,本文提出皮带机产能提速增效解决方案,通过实际生产检验,改造后的临港企业皮带运输能力整体大幅提高,产生了较好的经济效益和社会效益。     

Monetary Equilibrium and the Cost of Banking Activity

We investigate the effects of banks' operating costs on allocations and welfare in a low interest rate environment. We introduce an explicit production function for banks in a microfounded model where banks employ labor resources, hired on a competitive market, to run their operations. In equilibrium, this generates a spread between interest rates on loans and deposits, which reflects the underlying monetary policy and the efficiency of financial intermediation. In a deflation or low-inflation environment, equilibrium deposits yield zero returns. Hence, banks soak up labor resources to offer deposits that do not outperform idle balances, thus reducing aggregate efficiency.     

Estimating the effects of nutrition label use on Canadian consumer diet‐health concerns using propensity score matching

The overarching goal of nutrition labelling is to transform intrinsic credence attributes into searchable cues, which would enable consumers to make informed food choices at lower search costs. This study estimates the impact of nutrition label usage on Canadian consumers’ (n = 8,114) perceived diet‐health concerns using alternative propensity score matching (PSM) techniques. We apply a series of tests and sensitivity analyses to overcome issues of endogeneity and selection bias frequently found in studies of diet‐health behaviour and to validate the impact of exposure to nutrition facts labels for users vs. non‐users. Our results support the notion that consumer uncertainty and related food‐health concerns are linked to their information behaviour, but not in straightforward manner. Dominant subjective food attributes, such as taste, convenience and affordability, may in fact outweigh the benefits of information about healthier, alternative food choices. In order to change dietary health behaviour, food manufacturer and policy makers alike need to adopt communication instruments that better account for differences in preferences, shopping habits and overall usage patterns of nutrition labelling information.     

Confidence Intervals for the Area Under the Receiver Operating Characteristic Curve in the Presence of Ignorable Missing Data

Receiver operating characteristic curves are widely used as a measure of accuracy of diagnostic tests and can be summarised using the area under the receiver operating characteristic curve (AUC). Often, it is useful to construct a confidence interval for the AUC; however, because there are a number of different proposed methods to measure variance of the AUC, there are thus many different resulting methods for constructing these intervals. In this article, we compare different methods of constructing Wald‐type confidence interval in the presence of missing data where the missingness mechanism is ignorable. We find that constructing confidence intervals using multiple imputation based on logistic regression gives the most robust coverage probability and the choice of confidence interval method is less important. However, when missingness rate is less severe (e.g. less than 70%), we recommend using Newcombe's Wald method for constructing confidence intervals along with multiple imputation using predictive mean matching.     

隔代照料孙子女对中老年人心理健康的影响研究

使用 2013 年中国健康与养老追踪调查(CHARLS)数据，以抑郁情况与生活满意度作为 心理健康的代理指标，探讨隔代照料孙子女对中老年人心理健康的影响，为克服由于自我选择所 产生的内生性问题，进一步运用倾向得分匹配法分析隔代照料孙子女对中老年人心理健康的影响。 研究结果表明，我国 51.7% 的中老年人提供隔代照料;提供隔代照料对中老年人心理健康有显著 的改善作用;隔代照料孙子女对男性、农业户口、未达到退休年龄中老年人影响更为显著;此外， 对影响路径的分析表明，提供隔代照料会通过显著增加人们参加社交活动的可能性以及参加社交 活动的频率来改善心理健康。     

Superstition and real estate prices: transaction-level evidence from the US housing market

We investigate the impact of superstition on prices paid by Chinese-American home buyers. Chinese consider 8 lucky and 4 unlucky. Lacking explicit buyer ethnicity identifiers, we develop a binomial name classifier, a machine learning approach applicable to any data set containing names, that allows for falsification tests using other ethnic groups, and mitigates ambiguity from the transliteration of Chinese characters into the Latin alphabet. Chinese buyers pay 1–2% premiums for addresses including an 8 and 1% discounts for addresses including a 4. These results are unrelated to unobserved property quality; no premium exists when Chinese sell to non-Chinese. The persistence of superstitions reflects the extent of cultural assimilation.