The strategic bombing of German cities during World War II and its impact on city growth

It is a stylized fact that city size distributions are rather stable over time. Explanations for city growth and the resulting city-size distributions fall into two broad groups. On the one hand there are theories that assume city growth to be a random process and this process can result in a stable city-size distribution. On the other hand there are theories that stress that city growth and the city-size distribution are driven by economically relevant differences between locations. These differences might be the result of physical differences or might be caused by location specific increasing returns or externalities. We construct a unique data set to analyze whether or not a large temporary shock had an impact on German city growth and city size distribution. Following recent work by Davis and Weinstein (2001) on Japan, we take the strategic bombing of German cities duringWWII as our example of such a shock. The goal of this paper is to analyze the impact of this shock on German city-growth and the resulting citysize distribution. If city-growth follows a random walk this would imply that the war shock had a permanent impact on German city-growth. If, however, as the second group of theories predicts, the random walk hypothesis is not confirmed this would mean that the war shock at most had a temporary effect on the city growth process. Our main finding is that city growth in western Germany did not follow a random walk, while city growth in eastern Germany did follow a random walk. Different post-war economic systems are most likely responsible for this outcome.

Putting new economic geography to the test: free-ness of trade and agglomeration in the EU regions

Based on a new economic geography model by Puga (1999), we use the equilibrium wage equation to estimate two key structural model parameters for the NUTS II EU regions. The estimation of these parameters enables us to come up with an empirically based free-ness of trade parameter. We then confront the empirically grounded free-ness of trade parameter with the theoretical relationship between this parameter and the degree of agglomeration. This is done for two versions of our model: one in which labor is immobile between regions, and one in which labor is mobile between regions. Overall, and in line with related studies, our main finding is that agglomeration forces still have only a limited geographical reach in the EU. Agglomeration forces appear to be rather localized

Putting New Economic Geography to the Test: Free-ness of Trade and Agglomeration in the EU Regions

Based on a new economic geography (NEG) model by Puga (1999), we use the equilibrium wage equation to estimate two key structural model parameters for the NUTS II EU regions. These estimations enable us to come up with an empirically grounded free-ness of trade parameter. In line with NEG theory, the estimation results show that a spatial wage structure exists for the EU regions. By going back to the theoretical model we then analyze the implications of the free-ness of trade parameter for the degree of agglomeration. Our main findings suggest that agglomeration forces still have only a limited spatial reach in the EU. Agglomeration forces appear to be rather localized. At the same time, confronting our empirical results with the underlying new economic geography model also brings out the limitations of empirical research in new economic geography.

The Empirical Relevance of the New Economic Geography: Testing for a Spatial Wage Structure in Germany

In this paper we want to shed some light on the empirical relevance of the new economic geography. Using one of the central features of the core new economic geography models, namely that wages have the tendency to fall the further one moves away from centres of economic activity, we investigate the existence of a spatial wage structure for post-unification Germany. We find support for a spatial wage structure for German city-district wages, and hence indirectly for the relevance of a new economic geography model for Germany. We also find that demand linkages in Germany are strongly localised and that the “old” border still matters to the extent that economic interactions between western and eastern Germany are still limited compared to the situation within these two parts of Germany.New economic geography, spatial wage structure, Germany

The Strategic Bombing of German Cities during World War II and its Impact on City Growth

We construct a unique data set to analyze whether or not a large temporary shock had an impact on German city growth and city size distribution. Following recent work by Davis and Weinstein (2001) on Japan, we take the strategic bombing of German cities during WWII as our example of such a shock. The goal of this paper is to analyze the impact of this shock on German city-growth and the resulting city-size distribution. If city-growth follows a random walk this would imply that the war shock had a permanent impact on German city-growth. If, however, as a second group of theories predicts, the random walk hypothesis is not confirmed this would mean that the war shock at most had a temporary effect on the city growth process. Our main finding is that city growth in western Germany did not follow a random walk, while city growth in eastern Germany did follow a random walk. Different post-war economic systems are most likely responsible for this outcome.

Looking for Multiple Equilibria when Geography Matters: German City Growth and the WWII Shock

Many modern trade and growth models are characterized by multiple equilibria. In theory the analysis of multiple equilibria is possible, but in practice it is difficult to test for the presence of multiple equilibria. Based on the methodology developed by Davis and Weinstein (2004) for the case of Japanese cities and WWII, we look for multiple equilibria in a model of German city growth. The strategic bombing of Germany during WWII enables us to assess the empirical relevance of multiple equilibria in a model of city-growth. In doing so, and in addition to the Davis and Weinstein framework, we look at the spatial inter-dependencies between cities. The main findings are twofold. First, multiple equilibria seem to be present in German city growth. Our evidence supports a model with 2 stable equilibria. Second, the explicit inclusion of geography matters. Evidence for multiple equilibria is weaker when spatial interdependencies are not taken into account.

Adding Geography to the New Economic Geography

For reasons of analytical tractability, new economic geography (NEG) models treat geography in a very simple way: attention is either confined to a simple 2-region or to an equidistant multi-region world. As a result, the main predictions regarding the impact of e.g. diminishing trade costs are based on these simple models. When doing empirical or policy work these simplifying assumptions become problematic and it may very well be that the conclusions from the simple models do not carry over to the heterogeneous geographical setting faced by the empirical researcher or policy maker. This paper tries to fill this gap by adding more realistic geography structures to the Puga (1999) model that encompasses several benchmark NEG models. By using extensive simulations we show that many, although not all, conclusions from the simple models do carry over to our multi-region setting with more realistic geography structures. Given these results, we then simulate the impact of increased EU integration on the spatial distribution of regional economic activity for a sample of 194-NUTSII regions and find that further integration will most likely be accompanied by higher levels of agglomeration.

Relaxing Hukou - Increased Labor Mobility and China’s Economic Geography

China’s Hukou system poses severe restrictions on labor mobility. This paper assesses the consequences of relaxing these restrictions for China’s internal economic geography. We base our analysis on a new economic geography model. First, we obtain estimates of the important model parameters on the basis of information on 264 of China’s prefecture cities over the period 1999-2005. Second, and by using our estimation results as input, we simulate various long-run scenarios of China’s internal economic geography that differ in their degree of interregional labor mobility. We find that increased labor mobility will lead to more pronounced core-periphery outcomes. Interestingly, these agglomerations are not necessarily along the coastal regions. Given the increased importance of China’s internal market, firms agglomerate in the populous heartland of China. China’s internal demand will be the most important determinant of its future economic geography.Empirical and Theoretical Methods

A Century of Shocks: The Evolution of the German City Size Distribution 1925 – 1999

The empirical literature on city size distributions has mainly focused on the USA. The first major contribution of this paper is to provide empirical evidence on the evolution and structure of the West-German city size distribution. Using a unique annual data set that covers most of the 20th century for 62 of West-Germany's largest cities, we look at the evolution of both the city size distribution as a whole and each city separately. The West-German case is of particular interest as it has undergone major shocks, most notably WWII. Our data set allows us to identify these shocks and provide evidence on the effects of these `quasi-natural experiments' on the city size distribution. The second major contribution of this paper is that we perform unit-root tests on individual German city sizes using a substantial number of observations to analyze the evolution of the individual cities that make up the German city size distribution. Our main findings are twofold. First, WWII has had a major and lasting impact on the city size distribution. Second, the overall city size distribution does not adhere to Zipf's Law. This second finding is largely based on the results of unit root tests for individual cities to test for Gibrat's Law, the latter being a requirement for Zipf's Law to hold for the overall city-size distribution. Together these two findings are consistent with theories emphasizing increasing returns to scale in city growth.

The final frontier? Border effects and German regional wages

Recent studies of border effects have focused on the intra-country and inter-country comparison of trade flows. It is found that borders have a negative impact on the size of cross-border trade. In order to estimate border effects on a regional level one needs not only data on inter-country but also on intra-country trade. For many countries (regional) data on intra-country trade are simply lacking, which makes an analysis of border effects and border regions cumbersome. In this paper we take a different approach to measure the impact of borders. We estimate a market potential function for German regional wages and by analysing whether German border regions can be distinguished from the other regions in terms of their wages. We use a market potential function because its basic idea (regional wages fall the further one moves away from economic centers) can be grounded on different trade theories and also because the resulting wage equation is related to border effect studies based on trade flows. We use a data set for 441 German districts for the years 1992 and 1995. In general, we find some evidence that is consistent with the existence of border effects but this evidence is probably better looked upon as an indication of a strong localisation of demand spillovers on regional wages in general. Even though border effects can not be ruled out, the overriding outcome is that of a strong localization of demand spill-overs for all German regions