Interpretation of Structural Parameters for Models with Spatial Autoregression

The main purpose of the article is to consider a important issue of spatial econometrics, which is a proper interpretation of structural parameters of econometric models with spatial autoregression. The problem will be considered basing on the example of the spatial SAR model. Another purpose of the article is to make an overview of measures of average spatial impact proposed by the subject literature (see Lesage and Pace 2009). The analysis will include such measures as Average Total Impact to an Observation, Average Total Impact from an Observation, Average Indirect Impact to an Observation, Average Indirect Impact from an Observation and Average Direct Impact. Having considered the above issues, I will introduce a set of three original measures that allow the interpretation of the strength of the impact of the explanatory processes within the spatial SAR model, which take the forms of average direct impact, average indirect impact and average induced impact. The use of this set of measures will be illustrated with the example of the analysis of the unemployment rate in Poland. It must be emphasized that the presented set of measures may also be designated for other spatial models. With the knowledge of the empirical form of the model and of the spatial weight matrix, the set of measures introduced simplifies significantly the complex procedure of the interpretation of the structural parameters for spatial models to the use of merely three values

Redefining The Modifiable Areal Unit Problem Within Spatial Econometrics, The Case of the Scale Problem

The paper focuses on the issue of the modifiable areal unit problem (MAUP), which is frequently discussed within spatial econometrics. This issue concerns the changeability of the characteristics of the analysed phenomena under the impact of the change in the composition of territorial units. The article indicates four conditions which need to be fulfilled if the correctness of spatial analyses is to be maintained. Also, the paper introduces the concept of the quasi composition of regions (QCR). It was defined as a set of particular compositions of territorial units for subsequent aggregation scales. Particular compositions of territorial units are selected in a way that allows a correct analysis within the undertaken research problem to be conducted. The chief asset of the paper is the proposal to redefine the concept of the modifiable areal unit problem. Both the scale problem and the aggregation problem were linked to the accepted quasi composition of regions. The redefinition of the concept is vital for the research conducted since analysing phenomena based on compositions of territorial units which are excluded from the quasi composition of regions leads to the formulation of incorrect conclusions. Within the undertaken research problem there exists only one particular composition of territorial units which allows the identification and description of the dependence for analysed phenomena. Within the considered modifiable areal unit problem two potential problems were defined and they can occur while making spatial analyses. The first is the final areal interpretation problem (FAIP) that occurs when the characteristics of phenomena or the dependence are designated for too large region. The other issue is the aggregation scale interpretation problem (ASIP). It occurs when a quasi composition of regions is enlarged by an aggregation scale where the correctness of the results of the undertaken research problem is not preserved. In both cases it is possible to reach a situation where the obtained characteristics will be deprived of the cognitive value

The Modifiable Areal Unit Problem – Analysis of Correlation and Regression

The paper focuses on the issue of the modifiable areal unit problem, which means a possibility of obtaining various results for spatial economic analyses depending on the assumed composition of territorial units. The major research objective of the work is to examine the scale problem that constitutes one of the aspects of the modifiable areal unit problem. Analysis of the scale problem will be conducted for two research problems, namely, for the problem of the causal relationships between the level of investment outlays in enterprises per capita and the number of entities of the national economy per capita, and the issue of the dependence between the registered unemployment rate and the level of investment outlays per capita. The calculations based on the empirical values of those variables have showed that moving to a higher level of aggregation resulted in a change in the estimates of the parameters. The results obtained were the justification for undertaking the realisation of the objective. The scale problem was considered by means of a simulation analysis with a special emphasis laid on differentiating the variables expressed in absolute quantities and ones expressed in relative quantities. The study conducted allowed the identification of changes in basic properties as well as in correlation of the researched variables expressed in absolute and relative quantities. Based on the findings, it was stated that a correlation analysis and a regression analysis may lead to different conclusions depending on the assumed level of aggregation. The realisation of the research objective set in the paper also showed the need to consider the adequate character of variables in both spatial economic analyses and during the examination of the scale problem

Redefining the Modifiable Areal Unit Problem Within Spatial Econometrics, the Case of the Aggregation Problem

The paper focuses on the issue of the aggregation problem, which is frequently discussed within spatial econometrics. The aggregation problem is one of the two aspects of the modifiable areal unit problem (MAUP). The aggregation problem is connected with the volatility of the obtained results occurred when various compositions of territorial units for the same aggregation scale were applied. The objective of the present paper is to consider the redefinition of aggregation problem and showing positive solution of the aggregation problem based on the empirical example of determining agricultural macroregions.In the article the aggregation problem was defined as a problem of establishing a particular composition of territorial units at a selected aggregation scale in a such a way that is remains in the quasi composition of regions within the undertaken research problem. The paper also presented the procedure for determining agricultural macroregions where the analysis of the spatial volatility of the agrarian structure and the current knowledge on the agriculture in Poland were applied.In addition, the paper considered the final areal interpretation problem connected with the incorrect determination of the area in relation to which final conclusions are drawn. The problem was presented basing on the example of the establishment of the average concentration of the area of agricultural land in Poland with the use of the Gini index calculated for districts. The paper emphasised that ignoring the final areal interpretation problem in spatial analyses may lead to an apparent identification of the modifiable areal unit problem.

The Application Of Local Indicators For Categorical Data (LICD) In The Spatial Analysis Of Economic Development

Firstly, we identify classes of regions presenting different economic development levels using taxonomic methods of multivariate data analysis. Secondly, we apply a join-count test to examine spatial dependencies between regions. It examines the tendency to form the spatial clusters. The global test indicates general spatial interactions between regions, while local tests give detailed results separately for each region. The global test detects spatial clustering of economically poor regions but is statistically insignificant as regards well-developed regions. Thus, the local tests are also applied. They indicate the occurrence of five spatial clusters and three outliers in Poland. There are three clusters of wealth. Their development is based on a diffusion impact of regional economic centres. The areas of eastern and north western Poland include clusters of poverty. The first one is impeded by the presense of three indiviual growth centres, while the second one is out of range of diffusion influence of bigger agglomerations

Comparative Analysis of Natural and Synthesized Polish Speech

In the evolving field of speech synthesis, not only intelligibility, but also naturalness remains an important factor. This paper presents a comparative analysis of natural versus synthesized Polish speech. Speech synthesizers: Ivona, Mekatron, Notevibes, and ttsmp3 were explored. Four methods for assessing synthesized speech quality and comparing it to natural speech were presented: the AB test, MOS, logatom articulation test, and MUSHRA. Sentence databases and a database of logatoms were generated for each synthesizer and recorded for natural speech. Results indicated natural speech was consistently better than synthesized speech. Among the synthesizers, Notevibes performed best in all comparisons, while Mekatron ranked lowest

METROPOLITAN AREAS IN CENTRAL POLAND AND THEIR IMPACT ON MIGRATION FLOWS

The objective of the paper is to identify subregions (NUTS 3) of the central part of Poland pretending to metropolitan areas, as well as to study their impact on the domestic migration flows. Their social and economic situations in 2008 were determined on the basis of the composite measure values. Their participation in the domestic migration flows in the period 2008-2010, considering the directions, range and intensity of flows, was also examined. Only Warsaw is the completely shaped metropolitan area in Poland. The city demonstrates the highest economic potential and therefore the strongest migration flows and dependences with other subregions. The cities of Poznań and Łódź and also the Bydgosko-toruński subregion can be recognized as developing metropolitan areas. These subregions represent significant economic centres; however migration flows related to them demonstrate mainly regional importance

METROPOLITAN AREAS IN CENTRAL POLAND AND THEIR IMPACT ON MIGRATION FLOWS

        The objective of the paper is to identify subregions (NUTS 3) of the central part of Poland pretending to metropolitan areas, as well as to study their impact on the domestic migration flows. Their social and economic situations in 2008 were determined on the basis of the composite measure values. Their participation in the domestic migration flows in the period 2008-2010, considering the directions, range and intensity of flows, was also examined.        Only Warsaw is the completely shaped metropolitan area in Poland. The city demonstrates the highest economic potential and therefore the strongest migration flows and dependences with other subregions. The cities of Poznań and Łódź and also the Bydgosko-toruński subregion can be recognized as developing metropolitan areas. These subregions represent significant economic centres; however migration flows related to them demonstrate mainly regional importance

Renewable and Sustainable Energy: Current State and Prospects

Short review about Special Issue: "Renewable and Sustainable Energy: Current State and Prospects"