Supplier Search and Re-matching in Global Sourcing - Theory and Evidence from China

In this paper, we consider a dynamic search-and-matching problem of a firm with its intermediate input supplier. In our model, a headquarter currently matched with a supplier, has an interest to find and collaborate with a more efficient partner. However, supplier switching through search and re-matching is costly. Given this trade-off between the fixed costs and the expected gains from continued search, the process will stop whenever the headquarter has found a sufficiently efficient supplier. Using firm-product-level data of fresh Chinese exporters to the United States, we obtain empirical evidence in line with the predictions of our theory. In particular, we find that the share of short-term collaborations is higher in industries with more supplier-cost dispersion, an indication of higher expected search opportunities

The Importance of Spatial Autocorrelation for Regional Employment Growth in Germany

In analyzing the disparities of the regional developments in the volume of employment in Germany, in the recent empirical literature so called shift-share-regression-models are frequently applied. However, these models usually neglect spatial interdependencies, even though such interdependencies are likely to occur on a regional level. Therefore, this paper focuses on the importance of spatial dependencies using spatial autocorrelation in order to analyze regional employment development. Spatial dependency in the form of spatial lag, spatial error and cross regressive model are compared. The results indicate that the exogenous variables' spatial lag sufficiently explains the spatial autocorrelation of regional employment growth

De-Industrialisation, Entrepreneurial Industries and Welfare

We develop a two-sector general equilibrium model with monopolistic competition featuring nonhomothetic production and a variable demand elasticity for the manufactured goods. An increase in the relative price of manufacturing varieties can lead to a decline in total industrial output in our framework, i.e., to de-industrialisation. The two key mechanisms behind this surprising result are that the founding of firms requires skilled labour as a fixed input requirement, and that the price increase can raise the profit margin in the manufacturing industry and thereby induce firm entry. When the manufacturing sector mainly adjusts at the extensive margin, we refer to this industry as being entrepreneurial. Due to the fixed input requirement entry reduces the effective endowment of skilled labour available for production. This reduces industrial output owing to a novel generalized version of the Rybczynski effect. De-industrialisation occurs if that effect is sufficiently large in comparison with the standard output price effect for a given number of firms. Furthermore we prove the counterintuitive result that de-industrialisation implies a fall in the output per firm and under plausible conditions a rise in welfare. Our results shed new light on the current debates about possible causes of premature de-industrialisation and its welfare effects

Proposal of a Nutritional Quality Index (NQI) to Evaluate the Nutritional Supplementation of Sportspeople

Background: Numerous supplements are used by sportspeople. They are not always appropriate for the individual or the sports activity and may do more harm than good. Vitamin and mineral supplements are unnecessary if the energy intake is sufficient to maintain body weight and derives from a diet with an adequate variety of foods. The study objectives were to evaluate the main nutrients used as supplements in sports and to propose a nutritional quality index (NQI) that enables sportspeople to optimize their use of supplements and detect and remedy possible nutritional deficits. Material and Methods: A nutritional study was performed in 485 sportspeople recruited from Centros Andaluces de Medicina del Deporte, (CAMD). All completed socio-demographic, food frequency, and lifestyle questionnaires. The nutritional quality of their diet and need for supplementation were evaluated by scoring their dietary intake with and without supplementation, yielding two NQI scores (scales of 0-21 points) for each participant. Results: A superior mean NQI score was obtained when the supplements taken by participants were not included (16. 28 (SD of 3.52)) than when they were included (15.47 (SD: 3.08)), attributable to an excessive intake of some nutrients through supplementation. Conclusions: These results indicate that sportspeople with a varied and balanced diet do not need supplements, which appear to offer no performance benefits and may pose a health risk.The authors are grateful to the Junta de Andalucía, Spain (Research Group AGR-255“Nutrition. Diet and Risk Assessment”), a collaboration agreement with the Andalusian Centres of Sports Medicine (Junta de Andalucía) and the FPU program of the Spanish Ministry of Education and Science. Study participants were recruited through the project “Nutritional and diet assessment methodologies applied to the Andalusian sportsperson in Andalusian Sports centres”, Research project FMD2010SC0071 of the Junta de Andalucía

Data for: City age and city size

Abstract of associated article: Using novel data on the foundation dates of more than 10,000 American Census places, we show that older cities in the US tend to be larger than younger ones. To take this nexus between city age and city size into account, we introduce endogenous city creation into a dynamic economic model of an urban system. Our model predicts a pattern of age-dependent urban growth that is in line with recently established empirical evidence. The size distribution that emerges in our economy delivers a close fit to different types of US data and it outperforms other suggested parametrizations. This evidence can resolve several debates and build a bridge between different views in the literature on city size distributions

Trade, Wages, and Productivity

We develop a new general equilibrium monopolistic competition model with variable demand elasticity, heterogeneous firms, and multiple asymmetric regions. Wages, productivity, consumption diversity, and markups across firms and markets are all endogenously determined and respond to trade integration in a way that is consistent with empirical evidence. Using Canada-US regional data, we structurally estimate the model and simulate the impacts of removing all trade barriers generated by the Canada-US border. We find that Canadian average labor productivity increases by 8.03%, whereas US average labor productivity rises by just 1.02%. Consumers exposure to market power falls sizably by up to 12.11% in the Canadian provinces, and by up to 2.82% in the US states. At the firm level, however, markup changes are ambiguous and depend on the firms productivity and location. Our results suggest that markups on the firms side provide a very different piece of information than markups on the consumers side, which are central to any welfare statement