Neglected dynamics in panel data models; consequences and detection in finite samples*

The bias of various estimators for static cross-section and panel data models is assessed in a simulation study, where the actual data generating process is a dynamic adjustment mechanism with random individual effects. It is concluded that the consequences of incorrectly estimating a static model can be rather serious. Therefore, it is important to have an accurate technique available for the detection of dynamics. Two exact similar tests for the presence of a lagged dependent variable in panel data models are developed; in some simulation experiments these tests outperform standard asymptotic test procedures. Empirical results on Engle curves for food illustrate the above issues.     

招商引资竞争的有效性分析

本文利用一个简单的模型分析了区域招商引资竞争的有效性，在竞争的状态下，除区域间收益差额超过潜在不利的情况外，潜在不利区域将很难利用优惠改变企业固有区位，竞争使得分配更加有利于企业而不利于参与招商引资竞争的区域，而且这种招商引资竞争是难以避免的。认清本区域既有优势和关键行业比单纯提供优惠在招商引资过程中更加重要。     

Parental Compensatory Behaviors and Early Child Health Outcomes in Cebu, Philippines()

A dynamic optimization model of parents choosing investments in their children's health motivates an empirical model of parents' choices of health inputs for their children and the impacts of these decisions on their children's subsequent health. Estimates of the child health input demand functions and the child health production functions from the Cebu Longitudinal Health and Nutrition Survey accord with the prediction that optimizing behavior results in higher levels of aggregate child health. Observable parental behaviors respond to the physical developmental status of their children. These parental responses appear to yield large and statistically significant improvements in children's early physiological outcomes. However, because some health inputs choices are not observable, it is impossible to ascertain whether these measured effects are due solely to variations in the observed input choices.     

Adult Outcomes for Children of Teenage Mothers

Using data from the British Household Panel Survey, this study examines the relationship between several outcomes in early adulthood (e.g. education, inactivity, earnings and health) and being born to a teenage mother. Besides standard cross‐sectional multivariate regression estimates, we also present evidence from non‐parametric estimates and from estimates that account for unmeasured family background heterogeneity by comparing siblings born to the same mother who timed their births at different ages. Regardless of the econometric technique, being born to a teenage mother is usually associated with worse outcomes. An important channel of transmission of this adverse effect is childhood family structure, which plays a more powerful role than childhood family poverty. Albeit smaller, some of the detrimental effects are also found for children of mothers who gave birth in their early 20s.     

Uniform and Non-Uniform Second-Best Input Taxes

We investigate second-best, input-based taxes foragricultural nonpoint pollution control when marketprices are endogenous and production isheterogeneous. Theoretically, we derive the optimalforms of taxes which take account of heterogeneity(non-uniform taxes) and a tax which does not (auniform tax). Empirically, we use a multi-factor,market-equilibrium simulation model to determineoptimal tax rates and associated equity effects,particularly differences in landowner gains/lossesacross a heterogeneous region. When market prices areendogenous, second-best tax policies result inpecuniary externalities that affect existingenvironmental externalities. In particular, thepecuniary externalities amplify the effect of producerheterogeneity on determination of sub-regionaldifferences in tax rates and returns to land,particularly for the uniform policy. With endogenousprices, the uniform tax rate is considerably higherthan any of the non-uniform rates and, ironically, thenon-uniform taxes result in less dispersion oflandowner gains across sub-regions than the uniformtax.     

Spatial Interaction,Spatial Multipliers and Hospital Competition

The hospital competition literature shows that estimates of the effect of local market structure (concentration) on pricing (competition) are sensitive to geographic market definition. Our spatial lag model approach effects smoothing of the explanatory variables across the discrete market boundaries, resulting in robust estimates of the impact of market structure on hospital pricing, which can be used to estimate the full effect of changes in prices inclusive of spillovers that cascade through the neighboring hospital markets. The full amount, generated by the spatial multiplier effect, is a robust estimate of the impacts of market factors on hospital competition. We contrast ordinary least squares and spatial lag estimates to demonstrate the importance of robust estimation in analysis of hospital market competition. In markets where concentration is relatively high before a proposed merger, we demonstrate that Ordinary Least Squares (OLS) can lead to the wrong policy conclusion while the more conservative lag estimates do not.     

对普适性生产函数模型的一些改进

普适性生产函数方法为使用横截面数据估计时,由于各地区生产函数的不同所导致的不可估算问题,提供了很好地解决办法,但其参数的估计需用差分模型,这将产生严重的缺陷.文章放宽其基本假设,得到更一般的可估计模型——异方差模型,经验证据亦表明,改进后的模型优于原有模型.     

中国城镇居民家庭异质性与风险金融资产投资

运用2011年中国家庭金融调查（ CHFS）数据,研究了中国城镇居民家庭风险金融资产投资情况,实证中系统考虑了家庭异质性影响因素。主要的发现有：风险性金融资产比例在家庭资产净值达到约170万后开始下降,样本家庭的平均资产净值远离下降点;信贷约束的存在降低了风险资产的投资比例;家庭房产和风险金融资产之间是互补关系而非替代关系;健康状况、家庭医疗支出对医疗保险计划的影响至关重要;风险性金融资产比例在户主年龄达到约58岁后开始下降,样本家庭户主的平均年龄接近下降点。这些实证结论为政府提供了更具针对性的政策含义。     

Location choices under strategic interactions

We explore a fundamental aspect of firms' location choices largely overlooked in the literature: strategic interaction. We formalize the notion that strategic interaction renders collocation less appealing by fostering competition, which erodes firms' profits. Strategic interaction also impacts location choices across time. Specifically, because firms learn by doing in markets, location choices are shaped by two novel effects: entrenchment benefits from entering early in a market and improving capabilities relative to rivals, and opportunity costs from postponing entry to other markets where rivals enter and learn. When learning is local, firms collocate more: rivals are preempted from improving relative capabilities in higher‐value markets. However, when learning is global, firms collocate less: they can transfer capabilities from lower‐value to higher‐value markets, blocking rivals from achieving entrenchment benefits. Copyright © 2013 John Wiley & Sons, Ltd.