Testing constancy of the error covariance matrix in vector models

In this paper a Lagrange multiplier test of the hypothesis that the covariance matrix of a multivariate time series model is constant over time is considered. It is assumed that under the alternative, the error variances are time-varying, whereas the correlations remain constant over time. Under the parameterized alternative hypothesis the variances may change continuously as a function of time or some observable stochastic variables. Small-sample properties of the test statistic are investigated by simulation. The assumption of constant correlations does not appear overly restrictive.     

Robust Small Area Estimation under Spatial Non‐stationarity

The effective use of spatial information in a regression‐based approach to small area estimation is an important practical issue. One approach to account for geographic information is by extending the linear mixed model to allow for spatially correlated random area effects. An alternative is to include the spatial information by a non‐parametric mixed models. Another option is geographic weighted regression where the model coefficients vary spatially across the geography of interest. Although these approaches are useful for estimating small area means efficiently under strict parametric assumptions, they can be sensitive to outliers. In this paper, we propose robust extensions of the geographically weighted empirical best linear unbiased predictor. In particular, we introduce robust projective and predictive estimators under spatial non‐stationarity. Mean squared error estimation is performed by two analytic approaches that account for the spatial structure in the data. Model‐based simulations show that the methodology proposed often leads to more efficient estimators. Furthermore, the analytic mean squared error estimators introduced have appealing properties in terms of stability and bias. Finally, we demonstrate in the application that the new methodology is a good choice for producing estimates for average rent prices of apartments in urban planning areas in Berlin.     

Weak Disposability in Nonparametric Production Analysis with Undesirable Outputs

Weak disposability of outputs means that firms can abate harmful emissions by decreasing the activity level. Modeling weak disposability in nonparametric production analysis has caused some confusion. This article identifies a dilemma in these approaches: conventional formulations implicitly and unintentionally assume all firms apply uniform abatement factors. However, it is usually cost-effective to abate emissions in those firms where the marginal abatement costs are lowest. This article presents a simple formulation of weak disposability that allows for non-uniform abatement factors and preserves the linear structure of the model.     

Does strategy matter? A comparison of broadband rollout policies in Finland and Sweden

This study investigates broadband policies applied in Finland and Sweden with special reference to the geographical coverage of the required network infrastructure. These two Nordic countries are seen as forerunners in the development of the information society, and they also share several other similarities bearing relevance to the take-up of broadband. However, they have applied different broadband strategies: Sweden, one of the first-movers in this field, already launched its ambitious and interventionist national ICT infrastructure program in 2000, whereas the Finnish broadband strategy, published in 2003, largely relies on market forces. The present article analyses these broadband strategies, and attempts to identify their actual differences. It appears that the Finnish strategy caused temporary higher broadband prices and a somewhat slower rollout. However, the current results of the two countries’ strategies in terms of coverage and usage levels, as well as end-user prices, do not indicate any significant long-term policy-induced impacts.     

ESTIMATING THE INTERNAL RATE OF RETURN FROM PUBLISHED FINANCIAL STATEMENTS

This paper presents a new approach to estimating the longrun internal rate of return (IRR) for the firm from the accountant's rate of profit based on published financial statements. The model developed for estimating the IRR includes both capital and net working asset investments. Modelling and estimating the growth of the firm is an integral part of the approach. Furthermore, estimating the parameters describing the long-run financing behavior of the firm is presented based on discounted average funds flow statements. Finally, the approach is applied on the financial data of a large Finnish business enterprise.     

IS THERE A CURSE OF RELOCATION? ANALYSING THE CAUSAL LINK BETWEEN OFFSHORING AND THE INNOVATION PERFORMANCE OF (SMALL) FIRMS

We analyse the empirical link between offshoring activities and different dimensions of innovation performance at the firm‐level. In order to identify causal effects running from offshoring to innovation, we use a quasi‐experimental comparison group approach by means of (conditional) difference‐in‐difference estimations applied to German establishment‐level data for firms that conducted offshoring activities in the period 2007–13. We find that the international relocation of business functions has a negative impact on the firms’ propensity to be innovative in terms of product and process innovations as well as product improvements. While for larger firms the reduction in process innovations is most striking, potentially due to a lack of resources, stagnation in expertise and a reduction in intra‐organizational learning‐by‐doing associated with the relocation of some business activities, for small and medium‐sized enterprises we particularly observe a reduction in product innovations after the offshoring activity has taken place. When interpreting this ‘pessimistic’ picture on the link between offshoring and the innovation performance of firms, the reader should note that our findings for German establishments have to be assessed through the lens of a global economy in economic recession after 2008, which may have intensified the negative impact of offshoring on the firms’ innovation performance.     

ADVERSE SELECTION IN DYNAMIC MATCHING MARKETS

We study the Akerlofian adverse selection problem in a dynamic matching model where the competitive situation varies across different meetings. The ‘lemons principle’ is shown to limit the high quality sales within a wider range of quality distributions than in the Walrasian benchmark. High quality goods can nevertheless be traded, albeit less frequently than the low quality goods. For certain quality distributions, there exists a ‘partially pooling’ steady state where high quality sellers are active whenever at least two buyers compete for the good. Otherwise, the model features cycles in a sense that high quality goods are traded only in non‐consecutive periods.     

Aufschwung in Deutschland festigt sich trotz weltwirtschaftlicher Risiken

The German economy is already in the fifth year of a moderate upturn, which will continue in 2018. Global economic activity is also expanding rapidly. The increase in economic policy uncertainty seems to have few adverse effects on the world economy. The economic policy agenda of the new US government carries both risks and opportunities for the economic outlook for the US and the world. The Joint Economic Forecast predicts consumer prices in advanced economies to increase by 1.9% in 2018 and expects a change in the ECB’s policy.