Candidate stability and nonbinary social choice

Summary. The requirement that a voting procedure be immune to the strategic withdrawal of a candidate for election can be formalized in different ways. Dutta, Jackson, and Le Breton (Econometrica, 2001) have recently shown that two formalizations of this candidate stability property are incompatible with some other desirable properties of voting procedures. This article shows that Grether and Plott's nonbinary generalization of Arrow's Theorem can be used to provide simple proofs of two of their impossibility theorems. Received: August 15, 2001; revised version: March 11, 2002 RID="*" ID="*" Parts of this article were previously circulated in somewhat different form in a working paper with the same title by the second author. We are grateful to Michel Le Breton and an anonymous referee for their comments. Correspondence to:J.A. Weymark     

Assessing the Least Squares Monte-Carlo Approach to American Option Valuation

A detailed analysis of the Least Squares Monte-Carlo (LSM) approach to American option valuation suggested in Longstaff and Schwartz (2001) is performed. We compare the specification of the cross-sectional regressions with Laguerre polynomials used in Longstaff and Schwartz (2001) with alternative specifications and show that some of these have numerically better properties. Furthermore, each of these specifications leads to a trade-off between the time used to calculate a price and the precision of that price. Comparing the method-specific trade-offs reveals that a modified specification using ordinary monomials is preferred over the specification based on Laguerre polynomials. Next, we generalize the pricing problem by considering options on multiple assets and we show that the LSM method can be implemented easily for dimensions as high as ten or more. Furthermore, we show that the LSM method is computationally more efficient than existing numerical methods. In particular, when the number of assets is high, say five, Finite Difference methods are infeasible, and we show that our modified LSM method is superior to the Binomial Model.     

Expertenwissen im politischen Prozess — Nutzen,Grenzen und Gefahren

Since the outbreak of the financial and economic crisis, confidence in politicians as well as the economists in their advisory expert panels seems to be at an all-time low. Why do politicians reject science-based advice unless it fits into their political agenda? Are economists misunderstood by politicians and vice versa? The tension between the ideal of evidence-based policy-making and the reality of policy-based evidence-making is hardly a new phenomenon. Therefore, the expectation that Donald Trump, the Brexiteers and European populists will necessarily disappoint their voters because they simply cannot deliver what they have promised is misleading. Experts would be well advised to use the debate on the post-factual era as an impetus to reflect critically on their profession. One opinion expressed in this Zeitgespräch is that the contested societal and political impact of modern economics is due to its restricted scientific self-concept. A more open, pluralistic and transdisciplinary self-definition of economics would strengthen its societal influence. Another contributor ponders the proper incentives to persuade academic economists to provide economic policy advice. Key is the independence of advisory institutions like the German Council of Economic Experts. The selection of people with the best scientific qualifications will ensure the reputation of such institutions.     

The reverse tragedy of the commons: an exploratory account of incentives for under-exploitation in an open innovation environment*

This paper presents an empirical account of a phenomenon that we refer to as the ‘reverse tragedy of the commons’ in open innovation. The name signifies the ‘under-exploitation’ of intellectual property (IP) under weak appropriability. The name is this graphic because the tragedy is costly, and can also render IP effectively worthless and block innovation in the short to medium term. We propose that the tragedy is borne out of the interaction between enterprise characteristics, a competitive setting and the framework that is set by the policy intervention. This finding is pertinent to policy-makers with regard to the design of research, development and innovation instruments, as well as managers who must determine how to implement open practices in innovation.     

Rentenpaket: die Bundesregierung auf Irrwegen

In the summer of 2014 Germany will witness the most substantial expansion of pension expenditures since the 1950s. Yet, while this reform package was motivated mainly by the dismal prospect of rising old age poverty rates, it does little to alleviate this problem. On the contrary, its two central elements, an expansion of the pension claims of mothers whose children were born before 1992, and access to early retirement at age 63 for workers with a long insurance history, tend to benefit rather privileged groups of the insured. These measures endanger the sustainability of the German pension system and will necessitate future generations to work even longer than would have been the case otherwise.     

ECB Monetary Policy Surprises: Identification Through Cojumps in Interest Rates

This paper proposes a new econometric approach to disentangle two distinct response patterns of the yield curve to monetary policy announcements. Based on cojumps in intraday tick data of short‐ and long‐term interest rate futures, we develop a day‐wise test that detects the occurrence of a significant policy surprise and identifies the market perceived source of the surprise. The new test is applied to 133 policy announcements of the European Central Bank (ECB) in the period from 2001 to 2012. Our main findings indicate a good predictability of ECB policy decisions and remarkably stable perceptions about the ECB's policy preferences. Copyright © 2015 John Wiley & Sons, Ltd.