Detecting nonlinearity in time series by model selection criteria

This article analyzes the use of model selection criteria for detecting nonlinearity in the residuals of a linear model. Model selection criteria are applied for finding the order of the best autoregressive model fitted to the squared residuals of the linear model. If the order selected is not zero, this is considered as an indication of nonlinear behavior. The BIC and AIC criteria are compared to some popular nonlinearity tests in three Monte Carlo experiments. We conclude that the BIC model selection criterion seems to offer a promising tool for detecting nonlinearity in time series. An example is shown to illustrate the performance of the tests considered and the relationship between nonlinearity and structural changes in time series.     

The people behind the scenes: Episodic volunteering at fundraising events

Nonprofit organizations (NPOs) have become increasingly dependent on episodic volunteers (EVs), those that would help carry out an event with little training and expectation to commit to future events. Despite its importance to the survival of NPOs, the use of EVs with respect to fundraising has received little research focus. Furthermore, none of the existing studies identified examined how fundraising EVs differ from other EVs. This study seeks to contribute to our understanding of fundraising EVs using a global perspective. Data were generated using surveys distributed in seven countries, tallying more than 4,000 respondents. Variables included demographic characteristics, previous donation and volunteer history, motives, mode of volunteering, and overall experience. The data were analyzed by applying between-group (logistic regression on participation) and within-group analysis (ordered logistic regression on willingness to participate in the future). Data were further analyzed by examining differences by country. We found that country, gender, religion, income, employment, history of donations, mode of volunteering, and several motives, both intrinsic and extrinsic, were significant in the logistic regression analysis of participation in fundraising episodic volunteering. The ordered logistic analysis unexpectedly found that the only predictors to foster a willingness to engage again were the responsiveness of the event team and a desire to fulfill spiritual satisfaction. In recruiting and selecting EVs for fundraising events, NPOs should consider previous or current donors and those with regular volunteering experience and they should market volunteer opportunities towards those in search of spiritual fulfillment and meaning. Moreover, NPOs should prioritize quick and clear communication with fundraising EVs in order to foster a willingness to volunteer again. Lastly, NPOs should regularly assess for country-specific factors and contexts that may affect episodic volunteering in fundraising events. Our paper illustrates who fundraising EVs are, their motives, how they choose to volunteer, and what contributes to their willingness to volunteer again. Given the limited research on fundraising EVs, this study serves to help lay the foundation of research for this unique subgroup. Our aim was to not only address the dearth of literature but serve as a springboard for future research on fundraising EVs.     

Technical efficiency analysis correcting for biases from observed and unobserved variables: an application to a natural resource management project

This article brings together the stochastic frontier framework with impact evaluation methodology to compare technical efficiency (TE) across treatment and control groups using cross-sectional data associated with the MARENA Program in Honduras. A matched group of beneficiaries and control farmers is determined using propensity score matching techniques to mitigate biases stemming from observed variables. In addition, possible self-selection arising from unobserved variables is addressed using a selectivity correction model for stochastic frontiers recently introduced by Greene (J Prod Anal 34:15?C24, 2010). The results reveal that average TE is consistently higher for beneficiary farmers than the control group while the presence of selectivity bias cannot be rejected. TE ranges from 0.67 to 0.75 for beneficiaries and from 0.40 to 0.65 for the control depending on whether biases were controlled or not. The TE gap between beneficiaries and control farmers decreases by implementing the matching technique and the sample selection framework decreases this gap even further. The analysis also suggests that beneficiaries do not only exhibit higher TE but also higher frontier output.     

Uncertainty and central bank transparency: A non-Bayesian approach

We use a non-Bayesian approach to uncertainty, where “ambiguity” is taken into account, in order to analyze the issue of central bank transparency, and we underline that the use of such an approach may greatly change the results. We reconsider a specific argument against transparency found in the literature. We show that, in the presence of ambiguity, the argument can become a case in favor of transparency, which seems more in accordance with some stylized facts. Reduced Knightian uncertainty associated with increased transparency can contribute to making transparency beneficial.     

Assessment of innovative software technology: developing an end-user-initiated interface design strategy

Knowledge intensive services and, in particular, R&D services contribute significantly to innovation in firms. The objective of this paper is to find out which characteristics of firms explain the acquisition of R&D services and to analyse whether there are differences depending on the typology of the supplier (universities, technology centres and consulting firms). Three main conclusions emerge from the econometric estimations carried out with information from a survey of innovative firms in the region of Valencia in Spain. First, the results show that firm size and age matter in the decision to buy R&D services. Second, our results are consistent with the relevance that the literature gives to human capital in absorbing external knowledge. Third, innovation policy has a significant influence on the decision to acquire R&D services, particularly from universities and technology centres.     

A Survey of Textbooks for Industrial Organization and Public Policy

All teachers of economics will be interested in the author's dissection of the industrial organization course into its components. Teachers of this specialty will find this survey particularly useful for its examination of how the major texts treat each of the components.     

The Endurance and Eclipse of the Controlled Vote: A Formal Model of Vote Brokerage Under the Secret Ballot

Throughout much of mankind's experience with elections, vote brokers – local elites who direct the voting decisions of a subset of the electorate – have been able to make or break political careers. In various polities, brokers have thrived in spite of the secret ballot, a surprising outcome given that vote secrecy would ostensibly allow citizens to pocket the inducements offered by such individuals and vote their consciences anyway. To address this puzzle, we develop a framework for understanding the persistence and demise of vote brokerage under the secret ballot. In our model, a broker contracts with voters using an outcome contingent contract: some fixed benefit is promised to all voters sharing one of several observable profiles should the broker's candidate win the election. Using this framework, we demonstrate that the existence of brokerage depends on the size of the electorate contained within the jurisdiction controlled by the broker, with large jurisdiction sizes tending to drive brokerage out of existence. Moreover, we detail the manner in which the strategies employed by brokers depend on their economic power, the size of social groups, and ideological polarization. Empirical evidence from Minas Gerais, Brazil is used to evaluate the performance of the model.