The impact of collinearity on regression analysis: the asymmetric effect of negative and positive correlations

The purpose of this paper is to ascertain how collinearity in general, and the sign of correlations in specific, affect parameter inference, variable omission bias, and their diagnostic indices in regression. It is found that collinearity can reduce parameter variance estimates and that positive and negative correlation structures have an asymmetric effect on variable omission bias. It is also shown that the effects of collinearity are moderated by the relationship between the dependent variable and the regressors, a consideration not incorporated into most commonly used collinearity diagnostics. The formulae derived enable researchers to assess the sensitivity of regression results to the underlying correlation structure in the data.     

The effects of the Works Progress Administration's anti-malaria programs in Georgia 1932–1947

From 1900 to 1950, malaria rates declined rapidly in the southeast United States. At its peak, malaria infected over 30% of the population. Malaria declined over the period for several reasons: improvements in public infrastructure; development of new insecticides; improvements in agriculture that promoted drainage; increases in incomes; and changes in migration patterns. This paper focuses on public works constructed by the Works Progress Administration (WPA) during the 1930s and subsequent interventions during the 1940s. To estimate the relationship between these malaria programs and malaria rates, I construct a panel of annual county level malaria rates in Georgia from 1932 to 1947. Between 1932 and 1940 the malaria rate in counties that received WPA malaria projects fell from 25.9 deaths per 100,000 to 5.3 deaths per 100,000. The empirical estimates suggest that WPA malaria projects led to 9.1 fewer deaths per 100,000 or roughly 44% of the observed decline in treated counties. Additional public works constructed by the MCWA during World War II, and the introduction of DDT after 1945 completely eliminated malaria in Georgia by 1947.     

Entry Solicitation and Deterrence in R&D Competition with Spillovers

The purpose of this note is to examine incumbent behaviour and patterns of entry under R&D competition with spillovers. We find that, in addition to blockading, deterring and accommodating entry, the incumbent may also solicit entry. Entry solicitation occurs when the incumbent strategically alters its R&D commitment in order to take advantage of the spillover generated by the entrant's subsequent R&D investment. Although our results are placed in the context of R&D with spillovers, they are applicable to a wider class of models involving positive externalities, particularly network externalities.
JEL Classification Numbers: L12, O31.     

Clarence Ayres’s Critique of Orthodox Economic Theory

Mainstream economists and liberal politicians are criticizing the Third Way as it is being applied in the Netherlands. They argue that mutual consultation precludes an efficient adaptation to disturbances. The present study analyzes changes in wage and income policy in the Netherlands until 2005. It finds that wage and income policy has proven to be flexible enough to address “new” challenges in the Netherlands. The flexibility is rooted in a culture of tolerance that allows for some breaking of working rules. The latter arises from bounded socialization, that is, the imperfect transmission of information with respect to social working rules that result in similar but not identical copies of institutions.     

Executive Compensation: A Model of Disclosure Choice

Recent public policy debates have led to increased calls for full transparency of executive compensation. However, in practice, many firms are reluctant to disclose the full details of how they link executive compensation to performance. One possible reason for lack of full disclosure is that managers use their power to hide the details of their compensation plan in order to disguise opportunistic rent extraction. If this is the reason for secrecy, then public policy designed to force firms to provide full disclosure is unlikely to be resisted by shareholders. However, another possible explanation for less than full transparency is that some degree of secrecy about executive compensation may be in the interest of the company and its shareholders. If this explanation is correct, then public policy moves to increase transparency may be met by counter moves designed to protect managers and shareholders from such policies. In this paper we investigate if full disclosure of executive compensation arrangements is always optimal for shareholders. We develop a model where optimal executive remuneration solves a moral hazard problem. However, the degree to which the moral hazard problem affects the shareholders depends on hidden information, so that disclosure of the executive compensation scheme will typically reveal the hidden information, which can be harmful to shareholders. The model derives, therefore, the optimal disclosure policy and the optimal remuneration scheme. We find that the shareholders are better off pre‐committing not to disclose the executive compensation scheme whenever possible. Executive directors are shown to be better off too in the absence of disclosure of executive compensation schemes. An argument for mandating disclosure is that it provides better information to shareholders but our analysis demonstrates that disclosure does not necessarily achieve this objective. The results suggest that less than full disclosure can be in the interest of shareholders, the reason for this being that disclosures cannot be made selectively to shareholders but will also be made to strategic opponents. This will be the case if the board of directors and the remuneration committee includes enough independent directors. Whether or not non‐disclosure to shareholders is in their interest is however an empirical matter involving a trade‐off between the proprietary costs associated with disclosure to shareholders and the costs of potential collusion between executive and non‐executive directors associated with non‐disclosure.     

A combination of differentiation and consolidation theory and risk-benefit analysis to examine decisions on mastitis prevention

Abstract

Mastitis infections cause severe pain in dairy cows and are the most costly illness to farmers. This study combined differentiation and consolidation (Diff-Con) theory with risk-benefit analysis to explore how risky decisions are perceived and justified after a decision has been taken. More specifically, using survey data from 428 Swedish dairy farmers, their decisions about adopting preventive measures to control mastitis (mastitis control options, MCO) in dairy herds were examined. The analyses included group comparisons with non-parametric rank tests and use of both ordinary least squared regression and seemingly unrelated regression analysis to examine how prior adoption of MCO affects farmers’ attitudes to the MCO. The results showed that MCOs already adopted were rated higher in perceived riskiness (if not implemented) and in expected benefit (for illness prevention) than non-adopted MCOs. Having made the decision to implement a strategy increased the likelihood of that decision being perceived as more beneficial (reducing mastitis) and risky (in terms of disease increase if not implemented), irrespective of the combination of strategies used on the farm, during the post-consolidation stage. No difference in perceived illness prevalence could explain the farmers’ rating of the MCOs. These findings suggest that there may be a path dependency in farmers’ decision-making with respect to MCO. This implies that novel MCOs may have difficulty in achieving wider implementation. These results have implications for the development of strategies to communicate best practices for use of MCOs and for new research on MCOs and farmers’ decision-making.