Critical values for unit root tests in seasonal time series

SUMMARY In this paper, we present tables with critical values for a variety of tests for seasonal and non-seasonal unit roots in seasonal time series. We consider (extensions of) the Hylleberg et al. and Osborn et al. test procedures. These extensions concern time series with increasing seasonal variation and time series with structural breaks in the seasonal means. For each case, we give the appropriate auxiliary test regression, the test statistics, and the corresponding critical values for a selected set of sample sizes. We also illustrate the practical use of the auxiliary regressions for quarterly new car sales in the Netherlands. Supplementary to this paper, we provide Gauss programs with which one can generate critical values for particular seasonal frequencies and sample sizes.     

FIRMS AND FLEXIBILITY

The United States and France have very similar labor productivity levels while there are considerable differences between the firm‐size distributions and firm dynamics in the two countries. To reconcile these observations we introduce a joint model of endogenous entrepreneurship and firm‐size dynamics with firing costs, unemployment benefits, entry costs, and a tax wedge between wages and labor costs. We use our model to analyze the role of these rigitidies in explaining firm dynamics and productivity patterns in the United States and France. We find that our model with all rigidities goes a long way in accounting for firm‐size differentials between the United States and France while generating similar labor productivity outcomes. (JEL C78, D21, E24, J6)     

WAR OF ATTRITION: EVIDENCE FROM A LABORATORY EXPERIMENT ON MARKET EXIT

We report an experiment designed to study whether inefficient firms are systematically driven from overcrowded markets. Our data set includes a series of 3,800 wars of attrition of a type modeled by Fudenberg and Tirole in 1986. We find that exit tends to be efficient and exit times conform surprisingly well to point predictions of the model. Moreover, subjects respond similarly to implementations framed in terms of losses as they do to those framed in terms of gains. (JEL D21, L11, C92)     

AMPLIFICATION IN SERVICE SUPPLY CHAINS: AN EXPLORATORY CASE STUDY FROM THE TELECOM INDUSTRY

Evidence on the impact of amplification effects on supply chain performance primarily has been derived from studies in manufacturing industries. In this article we reported on a case study from the telecommunication industry and aimed to analyze relevant root causes and associated countermeasures of the amplification phenomenon in service supply chains. Our case findings confirm the occurrence of upstream amplification of workload in the service supply chain, workload being a more appropriate measure for amplification effects in service supply chains than inventory levels. Not all of the root causes for amplification effects known from research in manufacturing environments were found to apply in this particular service context, especially those related to the use of inventory. In addition, our telecom case study highlighted a new root cause for amplification: interactions of high workloads and reduced process quality that start reinforcing each other once workloads pass a certain threshold. In this particular case, many of the known countermeasures to eliminate amplification did not apply, because of the specific characteristics of the service process, or yielded only limited results. A potentially very powerful countermeasure identified was to implement quality improvements throughout the service chain. This quality dimension links our research to the literature on service management in general, where service quality is on top of the research agenda.     

ENCLOSURE

We model the development of property rights as an endogenous process, driven by capital accumulation. Property rights internalize the portion of the return to capital that is otherwise treated as common property. This enclosure further encourages capital accumulation and sustains economic growth. We view effective property rights as multilateral agreements among agents that can only be implemented and sustained when agents are sufficiently patient. Patience is determined by the marginal product of capital; the marginal product of capital shrinks, and consequently patience increases, as capital grows. Hence, property rights can be established only when an economy is rich enough. ( JEL P14, O11, C73)     

TRACKING CUSTOMER SEARCH TO PRICE DISCRIMINATE

The electronic technologies of the Internet make it possible for sellers to track potential customers and discriminate between the informed and uninformed. In this article, we report an experiment that investigates the market impact of firms tracking customers and offering discriminatory prices based on search history. We find that consumers, on average, face the same prices when sellers have the ability to track customers and price discriminate as when sellers post a single price for all buyers. However, informed buyers receive lower prices when sellers can detect buyer search, whereas uninformed buyers receive lower prices when firms cannot track customers. (JEL D43 , L13 , C92 )     

FIXED REVENUE AUCTIONS: THEORY AND BEHAVIOR

In this paper, we study auctions in which the revenue is fixed but the quantity is determined by the auction mechanism. Specifically, we investigate the theory and behavior of English quantity clock, Dutch quantity clock, last‐quantity sealed bid, and penultimate‐quantity sealed bid auctions. For theoretically equivalent fixed quantity and fixed revenue auctions, we find that fixed revenue auctions are robust to all the previously observed empirical regularities in fixed quantity auctions. (JEL C9, D4, L2)     

Competition in online job marketplaces: towards a global labour market for outsourcing services?

A new form of service outsourcing has emerged, namely the global online job marketplace for freelance contractors. Such platforms are currently the closest proxy to the idea of a global labour market where everyone competes for jobs regardless of location. In this article, we examine how competition manifests itself on one such global online platform, namely oDesk. We present a comparative analysis of the relative wages and the rewarding of skills and expertise of contractors from selected countries and investigate whether, via labour arbitrage, wage convergence takes place between Western and developing countries. We find that wage convergence is noticeable but experience and skills hardly translate into better remuneration. While service outsourcing (or microwork) via global online marketplaces provides new employment opportunities for freelancers around the world, the intense competition and the inherent restrictions of this type of marketplace limit the financial gains for most contractors.