Search results for "Omitted-variable bias"
showing 8 items of 8 documents
A Comprehensive Spatiotemporal Framework for Hedonic Pricing: Integrating the Comparable Sales Approach and Minimizing Spatial Omitted Variable Bias
2019
This paper develops a theoretical and methodological framework that integrates Hedonic Pricing (HP), grid comparable sales approach (CSA), and nearest neighbors into a general spatiotemporal specification. By explicitly providing a theoretical justification for introducing spatial (or spatiotemporal) econometrics to HP, this approach is not only relevant to house price forecasting and automated valuation models (AVM) but also to valuing environmental goods capitalized in housing and to all other fields employing house pricing models. The resulting econometric CSA and spatiotemporal Durbin models provide higher prediction accuracy and reliability to alternatives by reducing the spatially-del…
Irrigation water intensity and climate variability: an agricultural crops analysis of Italian regions
2020
This paper examines the relationship between the requirement of water resources for irrigation and climate variability and analyses the ranking of the best and worst performance of irrigation water intensity for each Italian region. To measure water resources demanded by agriculture, the irrigation water intensity (IWI) indicator has been computed as the ratio between volumes of irrigation water and total crop harvested. By applying panel data methodologies to a regional dataset spanning from 2000 to 2009, we may address heterogeneity and omitted variable issues. By merging meteo-climatic with agricultural variables, we may confirm that water precipitations, maximum temperature, irrigation …
TESTING FOR CONTAGION: A CONDITIONAL CORRELATION ANALYSIS
2005
Abstract In this paper, we test for contagion within the East Asian region, contagion being defined as a significant increase in the degree of comovement between stock returns in different countries. For this purpose, we use a parameter stability test, and, following [Rigobon, R., 2003a. On the measurement of the international propagation of shocks: is the transmission stable?, Journal of International Economics], we control for three types of bias, resulting from heteroscedasticity, endogeneity and omitted variable, respectively. The null of interdependence against the alternative of contagion is then tested as an overidentifying restriction. Unlike other studies, our approach is based on …
The Simpson paradox of school grading in Italy
2009
Abstract Data from the 2003 OECD-PISA Survey for Italy reveal a striking difference in the relationship between students’ competence (as measured by PISA score in Mathematics) and school grades across regions: a competence level granting bare sufficiency in the North yields excellence grades in the South. This has spurred a lively debate on education policy in the country, based on the inference drawn from this evidence that grading practices are excessively different in the two areas. We show in this note that this inference overlooks a Simpson paradox hidden in the data. After a more careful analysis, the above inference is seen to be wrong. The crucial omitted variable is the school-leve…
Aggregate uncertainty and sectoral productivity growth: The role of credit constraints
2016
Abstract We show that an increase in aggregate uncertainty—measured by stock market volatility—reduces productivity growth more in industries that depend heavily on external finance. The mechanism at play is that during periods of high uncertainty, firms that are credit constrained switch the composition of investment by reducing productivity-enhancing investment—such as on ICT capital—which is more subject to liquidity risks (Aghion et al., 2010). The effect is larger during recessions, when financing constraints are more likely to be binding, than during expansions. Our statistical method—a difference-in-difference approach using productivity growth of 25 industries from 18 advanced econo…
Estimating the gravity equation with the actual number of exporting firms
2013
Para estimar correctamente el efecto de los costes de comerciar sobre las exportaciones de las empresas, la ecuación de gravedad debe controlar por el número de empresas que opera en el mercado internacional. Debido a la ausencia de datos, estudios anteriores han controlado esta variable mediante técnicas econométricas que también pueden generar estimaciones sesgadas. Para superar estos problemas este trabajo estima una ecuación de gravedad utilizando una nueva base de datos de la OCDE y EUROSTAT , que incluye el número de empresas exportadoras en cada relación bilateral. Nuestros resultados muestran que no controlar el margen extensivo genera sesgos muy importantes en la estimación de los …
On the ambiguous consequences of omitting variables
2015
This paper studies what happens when we move from a short regression to a long regression (or vice versa), when the long regression is shorter than the data-generation process. In the special case where the long regression equals the data-generation process, the least-squares estimators have smaller bias (in fact zero bias) but larger variances in the long regression than in the short regression. But if the long regression is also misspecified, the bias may not be smaller. We provide bias and mean squared error comparisons and study the dependence of the differences on the misspecification parameter.
Is personality related to permanent earnings? Evidence using a twin design
2018
Using twin survey combined with register-based panel data on labor market outcomes, the authors examine the association between personality characteristics and long-term earnings among prime working-age individuals. The long-term earnings were measured over the 1990–2008 period. The sample contains 4,642 twin pairs, of which 53% are females. In contrast to previous studies, this paper uses the within-twin dimension of the data to control for shared family background and confounding genetic factors. The results suggest that unobserved genetic differences may introduce omitted variable bias in standard ordinary least square results. After controlling for shared environment and genetic backgro…