Binary switch portfolio

We propose herein a new portfolio selection method that switches between two distinct asset allocation strategies. An important component is a carefully designed adaptive switching rule, which is based on a machine learning algorithm. It is shown that using this adaptive switching strategy, the combined wealth of the new approach is a weighted average of that of the successive constant rebalanced portfolio and that of the 1/N portfolio. In particular, it is asymptotically superior to the 1/N portfolio under mild conditions in the long run. Applications to real data show that both the returns and the Sharpe ratios of the proposed binary switch portfolio are the best among several popular competing methods over varying time horizons and stock pools.     

On the uniqueness of subjective probabilities

Summary The purpose of this paper is twofold: First, within the framework of Savage (1954), we suggest axiomatic foundations for the representation of event-dependent preference relations over acts. This representation has the form of expectation of event-debendent utility with respect to non-unique subjective probabilities on the set of states. Second, we give an economic-theoretic motivation for selecting a unique probability distribution as an appropriate concept of subjective probabilities. However, unlike in Savage's theory, this notion of subjective probabilities does not necessarily represent the decisions-maker's belief regarding the likelihood of events.Our approach involves a departure from Savage's postulate P4, which guarantees the completeness of Savage's likelihood relation on the set of all events. Instead, we assume the existence of a finite partition of the set of states, {S ₁,...S _n}, such that, for events within each element of this partition P4 is satisfied. This weakening of Savage's axioms suffices for the existence of an expected event-dependent utility representation, but not for the uniqueness of the subjective probabilities.In many economic problems involving decision-making under uncertainty the existence of a unique probability is presumed and, in fact, is essential for the statement of the result. An example is Arrow's (1965) finding that all risk averse decision-makers will invest in a risky asset provided its expected rate of return exceeds that of an alternative risk-free asset. We show that a unique probability distribution can be chosen so as to render such results meaningful. Namely, any risk averse decision-maker will hold a positive position in the risky asset if and only if its expected rate of return with respect to the chosen probability exceeds that of the riskless asset.The research described in this paper began while the authors visited the Mathematisches Forschungsinstitut Oberwolfach, Germany. It was carried out in part while the second author visited the Santa Fe Institute in Sante Fe, New Mexico, USA and the Autonomous University of Barcelona, Spain. The second author would also like to acknowledge the financial support by NSF grant 911873.     

Determinants of demand for technology in relationships with complementary assets among Japanese firms

ABSTRACT

There has been growing interest in open innovation by firms creating new value by combining internal and external ideas. Technology insourcing, however, has not been satisfactorily investigated compared to technology outsourcing in empirical literature. In this paper, we examine the determinants of external technology sourcing by types of the counterpart in new product development (NPD). We use a novel dataset at the product level, conducted by RIETI in 2011. We highlight cases in which a technology partner is also a business partner, such as a supplier or customer, from those where this is not the case. In contrast, in cases when a technology partner is not a business partner, patents play an important role in moderating transaction costs in partnerships. In contrast, in cases when a technology partner is also a business partner, we found a pattern of co-specialization of managerial resources with the partner firm.

Abbreviations: B2B: Business to business; NPD: New product development; RBV: Resource-based view     

Toward a political budget cycle? Unveiling long-term latent paths in Greece

Quality & Quantity - Empirical studies demonstrated the existence of political budget cycles in many countries, although mechanisms underlying such cycles remain substantially unclear. The...