Estimation and Inference for Linear Panel Data Models Under Misspecification When Both n and T are Large

This article considers fixed effects (FE) estimation for linear panel data models under possible model misspecification when both the number of individuals, n, and the number of time periods, T, are large. We first clarify the probability limit of the FE estimator and argue that this probability limit can be regarded as a pseudo-true parameter. We then establish the asymptotic distributional properties of the FE estimator around the pseudo-true parameter when n and T jointly go to infinity. Notably, we show that the FE estimator suffers from the incidental parameters bias of which the top order is O(T^{? 1}), and even after the incidental parameters bias is completely removed, the rate of convergence of the FE estimator depends on the degree of model misspecification and is either (nT)^{? 1/2} or n^{? 1/2}. Second, we establish asymptotically valid inference on the (pseudo-true) parameter. Specifically, we derive the asymptotic properties of the clustered covariance matrix (CCM) estimator and the cross-section bootstrap, and show that they are robust to model misspecification. This establishes a rigorous theoretical ground for the use of the CCM estimator and the cross-section bootstrap when model misspecification and the incidental parameters bias (in the coefficient estimate) are present. We conduct Monte Carlo simulations to evaluate the finite sample performance of the estimators and inference methods, together with a simple application to the unemployment dynamics in the U.S.     

"Occupation" and the Movement of People within the Japanese Empire: An Exploration of Migration between the Japanese Southern Frontier and Colonial Taiwan, the 1920s−1930s

Abstract:  Although there have been few studies on Yaeyama (the southern end of Ryukyu Archipelago) locals' migration during the pre Asia-Pacific period, a significant number of people went from there to colonial Taiwan, in particular during the 1920s and 1930s. In this paper, I discuss why many locals of Yaeyama worked in colonial Taiwan by analysing narratives of former migrants in autobiographies and my own interview research. First, this paper demonstrates how Yaeyama locals' attitudes to "work" and "occupation" were converted into more modern attitudes between the 1900s and the 1920s. Yaeyama locals often mention there being "no jobs" in their home islands, which justified their decision to go to Taiwan; but the discourse of "unemployment" should not be understood as a mere reflection of Yaeyama's economic condition, but also as a mark of change in people's attitude to the world. Since "work" and "occupation" are not just a matter of economic necessity, it could be said that Yaeyama locals searched for jobs in Taiwan not strictly in terms of economic profitability. Yaeyama locals went to colonial Taiwan, in search of "employment"; this action was closely associated with a financial motive, but it also implies development of self-worth as a social being. Although Yaeyama locals in Taiwan sometimes suffered ethnic discrimination from Japan proper, they were usually treated better than Taiwanese; Colonial Taiwan was an attractive destination to Yaeyama locals not only because Taiwan was more affluent and modernized, but also there were more opportunities for them to achieve social promotion in the context of the Japanese Empire.     

Not Just the Price of Food: Challenges of an Urban Agriculture Organization in Engaging Local Residents

This case study of a community‐supported agriculture (CSA) organization in New Orleans focuses on the lack of participation in the CSA market by the local residents despite its intentions, and how various constituencies diagnose the causes of the disengagement. Interview and ethnographic observation data indicate a general consensus on the economic constraints, but some non‐resident supporters of the organization attributed the issue to lack of knowledge about the food system or the benefits of local food consumption. The residents, on the other hand, pointed to spatial and sociocultural barriers that made the market and its location less accessible to them, including the produce selection and purchase options, convenience of access to the market, and the race‐related historical and spatial context of the market's location. These findings suggest that the food access concerns of the food justice movement may be more easily addressed than the food sovereignty concerns. Food as a unique resource poses an additional challenge for the movement to construct an effective food justice frame.     

Effects of parasitoid community structure upon the population dynamics of the honeysuckle leafminer,Chromatomyia suikazurae (Diptera: Agromyzidae)

Population dynamics of a leafminer,Chromatomyia suikazurae (Agromyzidae, Diptera) and its parasitoid community were studied for ten years at seven natural populations along an altitudinal gradient in Japan. This species which mines leaves of a forest shrub,Lonicera gracilipes (Caprifoliaceae), was attacked by 25 hymenopterous parasitoid species. Annually, the parasitoid community structure varied less within a population than among populations. The seven parasitoid communities were clustered into three groups corresponding to the altitudinal gradient: (a) lowland communities dominated by late-attacking, generalist pupal idiobiont eulophids and with highest species diversity, (b) hillside communities dominated by an early-attacking, specialist larval-pupal koinobiont braconid and (c) highland communities dominated by an early-attacking, generalist larval idiobiont eulophid. Annual changes of the host larval densities among the local populations were largely synchronous rather than cyclic. Among these populations, host density levels and mortality patterns greatly varied. By analyzing these inter-populational differences of host mortality patterns, the following conclusions were drawn: (1) The host mortality patterns were determined by the host utilization patterns of the locally dominant species. (2) The host pupal mortality but not larval mortality was related to species diversity but not to species richness itself of each parasitoid community. (3) Density dependence was detected only in pupal mortality at a lowland population dominated by late-attacking pupal parasitoids. These results suggest that interspecific interactions of parasitoids add additive effects to host population dynamics dissimilarly among local populations with different parasitoid communities.     

An assessment framework based on social perspectives and Analytic Hierarchy Process: A case study on sustainability in the Japanese concrete industry

This research introduces a framework for assessing concrete sustainability which is based upon the concept that technology is defined by stakeholders’ perspectives and which applied Analytic Hierarchy Process to translate these perspectives into quantifiable assessment values. A survey was conducted to identify important criteria, and several “design scenarios” were introduced which represent different value systems by varying criteria importance. Concrete materials with varying environmental impact were then assessed to observe the effect of different value systems and material properties, and it was found that the concrete with better properties was generally selected as most sustainable regardless of the design scenario.     

关于民族认同变化的研究——以云南楚雄地区白族和汉族的关系为例

大理历来有吸收外地文化创造自己地方文化的传统.对异文化持开放态度,通过与外来文化的接触和交流来突破原有文化的范围,并充实和丰富自己的传统文化是大理文化的特点.大理研究对了解中国的民族状况、历史与文化具有重要意义.云南部分白族先民被汉族同化,这是众所周知的史实.可是对于这种民族融合在何时、何地、在何种条件下发生等问题,很少有民族学家具体而细致地研究过.通过在云南楚雄市子午镇、东华镇,南华县雨露乡进行的田野调查,对当地人民族认同的各种说法、风俗、火葬墓、梵文碑、有关祖先原籍的记载进行分析,依据这些调查和史料,探索白族民族认同变化的条件.并提出现在楚雄地区的部分汉族可能是过去的白族先民"僰人"的观点.     

Seasonality and vertical structure of light-attracted insect communities in a dipterocarp forest in Sarawak

Nocturnal flying insects were collected monthly for 13 months using ultra violet light-traps set at various vertical levels in a weakly-seasonal, tropical lowland dipterocarp forest in Sarawak, Malaysia. Abundance, faunal composition, size distribution and guild structure of these samples were analyzed with respect to temperal and vertical distributions. The nocturnal flying insect community in the canopy level was highly dominated by fig wasps (84%) in individual number, and by scarabaeid beetles (28%) in weight. A principal component analysis on monthly catches detected non-random, seasonal trends of insect abundance. The first two principal trends were an alternation of wetter (September to January) and less wet seasons (February to August) and an alternation between the least wet (January to March) and the other seasons. Many insect groups were less abundant in the least wet season than the other seasons, whilst inverse patterns were found in Scarabaeidae and Tenebrionidae. Significantly positive and negative correlations between monthly catch and rainfall were detected only in ovule-feeders and in phloem-feeders, respectively. Delayed, significant negative correlations between monthly catch and 1–3 month preceding rainfall were more frequently detected in phytophages, phloem-feeders, seed-feeders, wood-borers and scavengers. The peak in abundance along vertical levels were found at the canopy level (35 m) for phloem-, ovule-, seed-, root-, fungal-feeders and nectar collectors, at an upper subcanopy level (25 m) for scavengers and aquatic predators, and at a middle subcanopy level (17 m) for ants. Catches at the emergent level (45 m) did not exceed those at the canopy level.     

Korean residents in Japan during the second world war: Official reports on rumours and public feeling

The article identifies some of the ways in which the ‘Victorian Gypsy’ was constructed by a group of authors known as Gypsy lorists, and develops reading strategies that highlight the politics of their writing, in particular using Jacques Derrida's theorisation of the archive. For the Victorians, it seemed that the Gypsy way of life would soon die out. The Gypsies' apparently imminent disappearance marks their world as delicate, natural and formerly pure. However, the structure of the archive means that the lorists' attempts to preserve their version of Gypsy culture are threatened from within: they hasten the forgetting of that which they would conserve and archivally silence Gypsy voices with their own. Claims of extinction have evidently been disproved, however, and new archives successfully augment what the lorists considered to be the last word on Gypsies in Britain.     

The exact distribution and density functions of a pre-test estimator of the error variance in a linear regression model with proxy variables

We consider a linear regression model when some independent variables are unobservable, but proxy variables are available instead of them. We derive the distribution and density functions of a pre-test estimator of the error variance after a pre-test for the null hypothesis that the coefficients for the unobservable variables are zeros. Based on the density function, we show that when the critical value of the pre-test is unity, the coverage probability in the interval estimation of the error variance is maximum.