Agnostic notes on regression adjustments to experimental data: Reexamining Freedman's critique

Freedman [Adv. in Appl. Math. 40 (2008) 180-193; Ann. Appl. Stat. 2 (2008) 176-196] critiqued ordinary least squares regression adjustment of estimated treatment effects in randomized experiments, using Neyman's model for randomization inference. Contrary to conventional wisdom, he argued that adjustment can lead to worsened asymptotic precision, invalid measures of precision, and small-sample bias. This paper shows that in sufficiently large samples, those problems are either minor or easily fixed. OLS adjustment cannot hurt asymptotic precision when a full set of treatment-covariate interactions is included. Asymptotically valid confidence intervals can be constructed with the Huber-White sandwich standard error estimator. Checks on the asymptotic approximations are illustrated with data from Angrist, Lang, and Oreopoulos's [Am. Econ. J.: Appl. Econ. 1:1 (2009) 136--163] evaluation of strategies to improve college students' achievement. The strongest reasons to support Freedman's preference for unadjusted estimates are transparency and the dangers of specification search.Comment: Published in at http://dx.doi.org/10.1214/12-AOAS583 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

International E-Banking: ICT Investments and the Basel Accord

This study investigates how the Basel Accord and Information and Telecommunications Technologies (ICT) investments affect the commercial banking industries across countries. We employ the stochastic frontier approach to explore a data set composed of commercial banks from 51 countries. We find that telecommunications investment reduces, and the Basel Accord proxy enhances, the cost efficiency of commercial banks under study. Moreover, it is found that ICT investments improve cost efficiencies of commercial banks for countries in which the regulations are consistent with the international supervision

Efficiency Gains from the Relative Size of Information Technology Investments

The contribution of information technology (IT) to organizational performance has been investigated extensively in the MIS research recently. In this paper, the relationship between the relative size of IT investments by firms and the productive efficiency is examined using stochastic frontiers. We find evidence that the level of IT investments has a positive effect on the firm’s productive efficiency, implying that the firms investing relatively more in IT are likely to be more efficient in their production processes than those that invest less

\u3cem\u3eRhizobium japonicum\u3c/em\u3e Mutants Defective in Symbiotic Nitrogen Fixation

Rhizobium japonicum strains 3I1b110 and 61A76 were mutagenized to obtain 25 independently derived mutants that produced soybean nodules defective in nitrogen fixation, as assayed by acetylene reduction. The proteins of both the bacterial and the plant portions of the nodules were analyzed by two-dimensional polyacrylamide gel electrophoresis. All of the mutants had lower-than-normal levels of the nitrogenase components, and all but four contained a prominent bacteroid protein not observed in wild-type bacteroids. Experiments with bacteria grown ex planta suggested that this protein was derepressed by the absence of ammonia. Nitrogenase component II of one mutant was altered in isoelectric point. The soluble plant fraction of the nodules of seven mutants had very low levels of heme, yet the nodules of five of these seven mutants contained the polypeptide of leghemoglobin. Thus, the synthesis of the globin may not be coupled to the content of available heme in soybean nodules. The nodules of the other two of these seven mutants lacked not only leghemoglobin but most of the other normal plant and bacteroid proteins. Ultrastructural examination of nodules formed by these two mutants indicated normal ramification of infection threads but suggested a problem in subsequent survival of the bacteria and their release from the infection threads

Relative Sizes of Information Technology Investments and Productive Efficiency: Their Linkage and Empirical Evidence

The contribution of information technology (IT) to organizational performance has been investigated extensively in recent IS research. A number of economic and financial measures have been employed by researchers to gauge the impact of IT on organizational performance. The results of previous research can be described as inconclusive at best. This paper uses stochastic frontiers to examine the relationship between the relative size of IT investments by firms and their productive efficiency in the production process. Assuming different production frontiers (including the popular generalized Cobb-Douglas, the more general Box-Cox transformation, and the most general Box-Tidwell transformation for the production process), we find consistent empirical evidence that the relative level of IT investments has a positive effect on the firm\u27s productive efficiency, implying that firms investing comparatively more in IT are likely to be more efficient in their production processes than those investing less. This study confirms the positive effect of IT on the firm\u27s efficiency in the production process, provides a source to explain the disappearance of the productivity paradox, and suggests a direction for future research that may integrate both economic and financial aspects of previous research on IT benefits

The Great Recession, the Resulting Budget Shortfalls, the 2010 Elections and the Attack on Public Sector Collective Bargaining in the United States

American public sector unions and collective bargaining have been subjected to a vicious attack under the auspices of balancing government budgets, promoting equity between private and public employees and limiting the impact of special interests on government policy. The American and world financial crisis of 2007 resulted in the Great Recession of 2008 and substantial budget shortfalls for local and national governments world-wide. This financial crisis and the resulting disintegration of aggregate demand and employment are eerily similar to the financial crisis and collapse that led to the Great Depression of the 1930’s. However, unlike the calamity of the 1930’s, in the present emergency American conservatives, funded by the moneyed class, are attempting to use the predicament as an opportunity to attack collective bargaining and other institutions of support and power for the American middle class. This grasp for power represents and assertion of power and control by the American upper class not experienced since rise of scientific management and the deskilling of jobs and the destruction of the trade union system of collective bargaining in the 1890’s. In this paper I will outline the recent attack on public sector unions’ power in the American economy and the accompanying changes, and proposed changes, in American law. I will briefly describe the impact of the recent financial crisis on the American economy and the balance sheets of American state and national governments and the opportunism of the American plutocracy in using this crisis to propose and enact legislation to undermine the institution of collective bargaining and political proponents for the Middle and Lower classes. In particular I will discuss the recent efforts in Indiana, Wisconsin, Ohio, and Michigan to severely limit or prohibit public sector collective bargaining and the political influence American public sector workers. This attack on collective bargaining amounts to the largest grab for economic and political power by the American upper class since the destruction of the labor guilds in the 1890’s and the rise of the gilded age from the 1890’s-1930’s