Áfaalapú diffúziós index a konjunktúrakutatásban.

The unexpected economic situation in the spring of 2020 can be considered the consequence of the restrictive measures necessitated by the COVID-19 pandemic. So far, it has never occurred in the history of modern statistics that several areas of the economy had to be shut down almost overnight. This resulted in a decrease in economic performance that was unpredictable with traditional estimation methods. Generally used econometric models extrapolate trends from preceding periods during forecasting, however, in such an extreme situation, previous correlations could not be used for estimation. Another problem is that the indicators of short-term, so-called flash estimates are mainly based on data of organizations with large economic weight, however, dynamics of the production of micro, small and medium-sized enterprises may differ significantly from these in the event of a large downturn. The situation in the spring of 2020 encouraged the examination of alternative economic indicators, of which the diffusion indexes are presented in this study. These indexes are used to identify crises affecting the whole economy and are based on the aggregation of various indicators of economic statistics, taking into account the direction of their changes. In an organizational approach, the diffusion indexes can be calculated on administrative or Big Data. The authors choose the former way and use VAT data. (A Big Data approach would be the use of e-invoices but in Hungary no such data are currently available in homogeneous time series.) In this study, first the history of diffusion indexes is introduced, then a VAT-based version of them is presented on Hungarian microdata, which are available at the end of the month following each quarter. Next, the methodology for developing the VAT-based index is described and time series are analysed from 2008 Q1 to 2020 Q4. The authors examine the usability of their index in light of the downturn unfolded in 2020. Based on the results, their diffusion index proves to be an effective tool to show the monthly dynamics of economic changes. [ABSTRACT FROM AUTHOR]