Patterns of poverty among elderly Americans: a latent class Markov model

This article studies poverty persistence and the role of social security programmes on poverty among elderly in the US. We use a Latent Markov model to disentangle unobserved heterogeneity and state dependence. Because of its dynamic nature, unobserved heterogeneity is modelled to vary over time. This allows to capture different latent states of poverty that change over time. Result indicates the existence of three unobserved types evolving over time according to their propensity to be poor. Moreover, a strong persistence in poverty especially for women, individuals living alone and ethnic minorities is found. Finally, the estimates indicate that giving social assistance tends to reduce poverty.     

Debt contract strictness and auditor specialization

The conflicts of interest among managers, shareholders and creditors resulting in agency costs, can be mitigated by restricting managers’ adverse behavior, through financial covenants to better align the various stakeholder interests. Thus, debt contract strictness represents an important aspect of agency costs between creditors, shareholders, and management that is not always captured by interest rates. The contract setting provides a unique opportunity to investigate how creditors may rely on auditors to alleviate information uncertainty stemming from reliance on management's financial reporting and thus alleviate the creditor's potential loss of invested capital. After controlling for borrower risks, loan characteristics, and audit factors, we show that auditor industry specialization is significantly associated with a reduction in the strictness of debt contracts, consistent with creditors viewing certain industry expert auditors as effective monitors against financial reporting manipulation aimed at the avoidance of debt covenant triggers that protect creditors against potential loss. Further, we find that the association between loan strictness and auditor specialization is attenuated by stronger corporate governance systems, external monitors, and prior lender relationships.     

The long-run reversal in the long run: Insights from two centuries of international equity returns

We perform the most comprehensive test of long-term reversal in national equity indices ever done. Having examined data from 71 countries for the years 1830 through 2019, we demonstrate a strong reversal pattern: the past long-term return negatively predicts future performance. The phenomenon is not subsumed by other established cross-sectional return patterns, including the value effect. The long-term reversal is robust to many considerations but highly unstable through time. Finally, our findings support the overreaction explanation of this anomaly.     

Assessing the contribution of artisanal fisheries to food security: A bio-economic modeling approach

Artisanal fisheries are an important food source in many developing regions. Quantitative bio-economic models are needed that comprehensively assess artisanal fisheries’ contribution to food security. Our model combines standard resource economics theory with the literature on food systems. It explains impacts of environmental variations and market development on output, prices and ultimately food security. The application to the Senegalese purse-seine fishery reveals that total sector rents account for 2% of per capita yearly food expenditures for the coastal inhabitants. We examine the relative importance of main drivers and the vulnerability of different regions. Market development plays a crucial role: The resource is of far greater relevance for remote regions.     

Factors affecting classroom participation and how participation leads to a better learning

The purpose of this paper is twofold. First, we analyze various course- and student-related factors that affect participation grades within several college accounting classes. The second purpose is to determine whether in-class participation grades have an effect on exam performance in these classes. We find that, unlike in liberal arts and sciences courses, in accounting courses, participation grades for female students do not differ from participation grades for their male counterparts, regardless of class level. Overall, course level and student major have no direct effect on participation grades; however, the accounting majors and students in the lower level courses have better attendance than do non-accounting majors and students in more advanced courses. We observe that class schedule, in particular class duration and semester, affects students’ participation performance. Lastly, we find that students who participate more in classroom discussions perform 25% better on exams than do those with lower participation grades. This relationship holds for the three elements of participation grading: frequency of participation, consistency of participation, and attendance.     

Ownership discrimination and private firms financing in China

This study examines the financing/funding of private firms in China. Our results show that private firms are significantly less funded through formal financing channels such as bank loans than state-owned firms, and hence have to resort to alternative financing such as trade credit. Consistent with the theoretical expectation and literature, there is a substitution effect between trade credit and bank loans for private firms, but this effect is much weaker compared to that of state-owned firms. Moreover, while the univariate comparisons indicate that private firms obtain more notes payable than state-owned firms, the multivariate regression analyses show that the relation between bank loan and notes payable is positive and indifferent between private and state-owned firms.     

Estimating yield curves of the U.S. Treasury securities: An interpolation approach

Following the approach of interpolation, this paper proposes the multiple exponential decay model to fit yield curves for both the U.S. TIPS market and the conventional Treasury security market. Several estimation methods, including the unconstrained/constrained nonlinear minimization, quadratic programming, and the iterative linear least squares, are applied to estimate the unknown parameters according to different curve‐fitting purposes. Comparisons between the proposed model and the alternatives show that the multiple exponential decay successfully (1) adapts to a variety of shapes associated with yield curves, (2) (partially) keeps in line with the economic interpretations of Nelson–Siegel summarized by Diebold and Li ( 2006 ), and (3) dominates the competing models in curve‐fitting performance measured by mean fitted‐price errors over the sample period. In addition, the exact specification of a nonparametric interpolation model is pinned down by applying three statistical tools, which enable us to jointly take into account validity, optimality, and parsimoniousness of the proposed model.     

Optimal social security tax with myopic agents

Myopic agents lack the foresight to save for their own old age. It is generally believed that correcting myopia is a rationale for a pay-as-you-go (PAYG) pension system. This view has been supported by existing literature showing that the optimal PAYG social security tax should increase when people are more myopic. In this paper we obtain new results opposed to the traditional view. By establishing a very standard general equilibrium OLG model with myopic agents and endogenized marginal product of capital, we show that the optimal social security tax should be lower when people are more myopic. Our numerical analysis also shows that the welfare cost of the social security tax increases with people's degree of myopia. These results suggest that correcting myopia is not a clear rationale for the PAYG social security.     

粮食安全与农业结构调整水平的协整分析*——以广东省为例

[目的]实现我国粮食安全与农业结构调整之间(即粮食增产和农民增收)关系的协调,较长时间以来是学界、政界关注的重要议题,但定量分析两者之间内在依存关系的研究一直欠缺。[方法]文章采用协整分析及Granger因果关系检验方法,以广东为例,对我国粮食安全(用粮食总产量来衡量)与农业结构调整水平之间的协整性及因果关系进行了研究。[结果]广东粮食总产量与反映农业结构调整水平的3个指标之间均存在长期均衡关系,且农作物播种面积中粮食作物面积对广东粮食总产量影响最大,每下降1%,粮食总产量下降0. 659 548%。短期内,反映农业结构调整水平的3个指标对广东粮食总产量的影响均存在波动,但由短期偏离拉向长期均衡的牵动作用均较弱。Granger因果关系检验表明农业在国民经济中的比重、农作物播种面积中粮食作物面积早期对广东粮食总产量产生单向影响,但影响程度相对较弱。[结论]提出应从农业结构调整以外的因素着手提高我国粮食安全水平,并通过调整农业区域结构去缓解我国粮食供求市场的结构性矛盾。