Consistent inference in fixed-effects stochastic frontier models

The classical stochastic frontier panel data models provide no mechanism to disentangle individual time invariant unobserved heterogeneity from inefficiency. Greene (2005a, b) proposed the so-called “true” fixed-effects specification that distinguishes these two latent components. However, due to the incidental parameters problem, his maximum likelihood estimator may lead to biased variance estimates. We propose two alternative estimators that achieve consistency for $n\to \infty$ with fixed $T$. Furthermore, we extend the Chen et al. (2014) results providing a feasible estimator when the inefficiency is heteroskedastic and follows a first-order autoregressive process. We investigate the behavior of the proposed estimators through Monte Carlo simulations showing good finite sample properties, especially in small samples. An application to hospitals’ technical efficiency illustrates the usefulness of the new approach.     

The social process of internet appropriation: Living in a digitally advanced country benefits less well-educated Europeans

We generalize and extend the sequential model proposed by the resources and appropriation theory to explain the digital divide in the European Union plus the United Kingdom (EU27+UK). We measure the theoretical constructs of the model with data provided by the EU and test the theoretical predictions using a partial least squares structural equation model. We find support for the hypothesized relationships but find that the effects vary depending on the digital development level of countries. While education overall is the primary determinant of the social production of digital inequalities, a country's digital development level is crucial for less well-educated Europeans. These findings have theoretical and practical implications: (1) they call into question the homogeneity of the effect of causal relationships and the assumption that individuals differ only in terms of motivation, access, and digital skills, and (2) they indicate that socially disadvantaged Europeans benefit from living in more digitally developed countries.     

Optimality and Robustness of the English Auction

In Milgrom and Weber's (1982, Econometrica50, 1089–1122) “general symmetric model,” under a few additional regularity conditions, the English auction maximizes the seller's expected profit within the class of all posterior-implementable trading procedures and fails to do so among all interim incentive-compatible procedures in which “losers do not pay.” These results suggest that appropriate notions of robustness and simplicity which imply the optimality of the English auction for a risk-neutral seller must impose “bargaining-like” features on the set of feasible trading mechanisms. Journal of Economic Literature Classification Numbers: D44, D82.     

Learning during audit tasks in the field: A model, methodology, and experiment

Learning during performance of auditing tasks in the field is modeled as a change in the state of an auditor's knowledge base that results from experience during performance of a task. Several hypotheses are proposed and, along with data obtained by means of behavior observation and concurrent verbal protocols, used to interpret the problem-solving behaviors of four first-year auditors who performed an unfamiliar but audit-related task in simulated auditing environments. Significant findings of learning during performance of the experimental task are reported. While the data show that the auditor-subjects continuously encountered new learning situations throughout the task, they are inconclusive regarding learning through improved knowledge content. On the other hand, significant evidence is found that the learning that did occur was manifest by a greater availability of the auditor-subjects' knowledge. The implications of these findings in terms of the nature of audit tasks and the development of more expert-like task behavior are discussed.     

Competitive decision making: Two and a half frames

We argue that the study of competitive decision making has been heavily influenced by the frames of reference that are adopted by researchers. The dominant economic frame and the emergent behavioral frame describe largely separate phenomena and have little overlap. Drawing from examples of learning in games and markets, we show how each of these frames falls short of capturing some interesting elements in competitive decisions. We then describe how a coevolutionary perspective may be emerging as an integrative paradigm for the study of competitive decisions.This paper was prepared for the conference, Understanding Competitive Decision Making. Comments by the participants of that conference and Paul Shoemaker are gratefully acknowledged, as are discussions with Colin Camerer, Eldar Shafir, and Sharoni Shafir.     

Challenges in approximating the Black and Scholes call formula with hyperbolic tangents

Decisions in Economics and Finance - In this paper, we introduce the concept of standardized call function and we obtain a new approximating formula for the Black and Scholes call function through...     

Ricardo on machinery: an analysis of Ricardo's examples

The examples that are reported in the famous chapter “On Machinery” added by Ricardo in the third edition of his Principles are reconstructed and analyzed. Two sets of assumptions that rationalize the examples presented by Ricardo are identified: a) the innovation concerns an agricultural commodity and does affect neither which land is marginal nor the technology applied on the marginal land; b) the innovation concerns a non-basic commodity. Ricardo was aware of these two facts and he seems to have used them respectively in the first and second of his examples.     

Pensions reforms,workforce ageing and firm-provided welfare

This paper investigates the impact of an exogenous increase in the legal retirement age on the firms’ propensity to provide welfare services voluntarily to their employees. To this purpose we exploit a unique information derived from the Rilevazione su Imprese e Lavoro (RIL), a survey conducted in 2015 on a large and representative sample of Italian firms. Applying different regression models we show that firms which were forced to give up previously planned hirings because of the Law 201/2011 (the so-called ‘Fornero pension reform’), increased the probability of providing welfare services at workplace. By referring to the sociological, human resource management and economic literature we then argue that a sudden increase in the legal retirement age may motivate the employers to establish welfare schemes as a way to cope with an ageing workforce. Our findings also hold when propensity score matching methods are used in order to control for sample selection issues.     

Testing for unit roots in time series models with non-stationary volatility

Many of the key macro-economic and financial variables in developed economies are characterized by permanent volatility shifts. It is known that conventional unit root tests are potentially unreliable in the presence of such behaviour, depending on a particular function (the variance profile) of the underlying volatility process. Somewhat surprisingly then, very little work has been undertaken to develop unit root tests which are robust to the presence of permanent volatility shifts. In this paper we fill this gap in the literature by proposing tests which are valid in the presence of a quite general class of permanent variance changes which includes single and multiple (abrupt and smooth-transition) volatility change processes as special cases. Our solution uses numerical methods to simulate the asymptotic null distribution of the statistics based on a consistent estimate of the variance profile which we also develop. The practitioner is not required to specify a parametric model for volatility. An empirical illustration using producer price inflation series from the Stock–Watson database is reported.