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IWH-Chef: Sachsen-Anhalt ist nicht nur ChemieReint GroppDie Welt, 2. März 2026
The paper presents a modification of the matching and difference-in-differences approach of Heckman et al. (1998) for the staggered treatment adoption design and a Stata tool that implements the approach. This flexible conditional difference-in-differences approach is particularly useful for causal analysis of treatments with varying start dates and varying treatment durations. Introducing more flexibility enables the user to consider individual treatment periods for the treated observations and thus circumventing problems arising in canonical difference-in-differences approaches. The open-source flexpaneldid toolbox for Stata implements the developed approach and allows comprehensive robustness checks and quality tests. The core of the paper gives comprehensive examples to explain the use of the commands and its options on the basis of a publicly accessible data set.
We study the importance of intangible capital (R&D, software, patents) for the measurement of productivity using firm-level panel data from German manufacturing. We first document a number of facts on the evolution of intangible investment over time, and its distribution across firms. Aggregate intangible investment increased over time. However, the distribution of intangible investment, even more so than that of physical investment, is heavily right-skewed, with many firms investing nothing or little, and a few firms having very large intensities. Intangible investment is also lumpy. Firms that invest more intensively in intangibles (per capita or as sales share) also tend to be more productive. In a second step, we estimate production functions with and without intangible capital using recent control function approaches to account for the simultaneity of input choice and unobserved productivity shocks. We find a positive output elasticity for research and development (R&D) and, to a lesser extent, software and patent investment. Moreover, the production function estimates show substantial heterogeneity in the output elasticities across industries and firms. While intangible capital has small effects for firms with low intangible intensity, there are strong positive effects for high-intensity firms. Finally, including intangibles in a gross output production function reduces productivity dispersion (measured by the 90-10 decile range) on average by 3%, in some industries as much as nearly 9%.
This study analyses empirically the effects of import competition on firm productivity (TFPQ) using administrative firm-level panel data from German manufacturing. We find that only import competition from high-income countries is associated with positive incentives for firms to invest in productivity improvement, whereas import competition from middle- and low-income countries is not. To rationalise these findings, we further look at the characteristics of imports from the two types of countries and the effects on R&D, employment and sales. We provide evidence that imports from high-income countries are relatively capital-intensive and technologically more sophisticated goods, at which German firms tend to be relatively good. Costly investment in productivity appears feasible reaction to such type of competition and we find no evidence for downscaling. Imports from middle- and low-wage countries are relatively labour-intensive and technologically less sophisticated goods, at which German firms tend to generally be at disadvantage. In this case, there are no incentives to invest in innovation and productivity and firms tend to decline in sales and employment.
Refugee integration requires broad support from the host society, but only a minority of the host population is actively engaged. Given that most individuals reciprocate kind behaviour, we examine the idea that the proportion of supporters will increase as a reciprocal response to refugees’ contributions to society through volunteering. Our nationwide survey experiment shows that citizens’ intentions to contribute time and money rise significantly when they learn about refugees’ pro-social activities. Importantly, this result holds for individuals who have not been in contact with refugees. We complement this investigation with experiments in the lab and the field that confirm our findings for actual behaviour.
The mission of a job does not only affect the type of worker attracted to an organisation, but may also provide incentives to an existing workforce. We conducted a natural field experiment with 267 short-time workers and randomly allocated them to either a prosocial or a commercial job. Our data suggest that the mission of a job itself has a performance enhancing motivational impact on particular individuals only, i.e., workers with a prosocial attitude. However, the mission is very important if it has been actively selected. Those workers who have chosen to contribute to a social cause outperform the ones randomly assigned to the same job by about 15 percent. This effect seems to be a universal phenomenon which is not driven by information about the alternative job, the choice itself or a particular subgroup.
>>A completely revised version of this paper has been published as: Dettmann, Eva; Giebler, Alexander; Weyh, Antje: flexpaneldid. A Stata Toolbox for Causal Analysis with Varying Treatment Time and Duration. IWH Discussion Paper 3/2020. Halle (Saale) 2020.<<
The paper presents a modification of the matching and difference-in-differences approach of Heckman et al. (1998) and its Stata implementation, the command flexpaneldid. The approach is particularly useful for causal analysis of treatments with varying start dates and varying treatment durations (like investment grants or other subsidy schemes). Introducing more flexibility enables the user to consider individual treatment and outcome periods for the treated observations. The flexpaneldid command for panel data implements the developed flexible difference-in-differences approach and commonly used alternatives like CEM Matching and difference-in-differences models. The novelty of this tool is an extensive data preprocessing to include time information into the matching approach and the treatment effect estimation. The core of the paper gives two comprehensive examples to explain the use of flexpaneldid and its options on the basis of a publicly accessible data set.
The value of social network analysis is critically dependent on the comprehensive and reliable identification of actors and their relationships. We compare regional knowledge networks based on different types of data sources, namely, co-patents, co-publications, and publicly subsidised collaborative Research and Development projects. Moreover, by combining these three data sources, we construct a multilayer network that provides a comprehensive picture of intraregional interactions. By comparing the networks based on the data sources, we address the problems of coverage and selection bias. We observe that using only one data source leads to a severe underestimation of regional knowledge interactions, especially those of private sector firms and independent researchers. The key role of universities that connect many regional actors is identified in all three types of data.
This article examines how trade shocks shape labour market imperfections that create market power in labour markets and prevent an efficient allocation of labour. I develop a framework for measuring such labour market distortions in monetary terms and document large degrees of those distortions in Germany’s manufacturing sector. Import competition can only exert labour market disciplining effects when firms rather than workers have labour market power. Otherwise, export demand and import competition shocks tend to fortify existing distortions by amplifying labour market power structures. This diminishes the gains from trade compared to a model with perfectly competitive labour markets.
In this study, we investigate whether and to what extent community managers in online collaborative communities can stimulate crowd activities through their engagement. Using a novel data set of 22 large online idea crowdsourcing campaigns, we find that active engagement of community managers positively affects crowd activities in an inverted U-shaped manner. Moreover, we evidence that intellectual stimulation by managers increases community participation, while individual consideration of users has no impact on user activities. Finally, the data reveal that community manager activities that require more effort, such as media file uploads instead of simple written comments, have a larger effect on crowd participation.
We use the locational pattern of clubs in four major professional football leagues in Europe to test the causal effect of changes in premier league membership on regional employment and output growth at the NUTS 3 level. We rely on the relegation mode of the classical round-robin tournament in the European model of sport to develop a regression-discontinuity design. The results indicate small and significant negative short-term effects on regional employment and output in the sports-related economic sector when clubs are relegated from the premier division of the respective football league. In addition, we find small negative effects on overall regional employment growth. However, total regional gross value added remains unaffected, indicating that in the main it is the less productive jobs that disappear in the short-term.
