arXiv subjects

Nazarii Salish

Publications and source records attributed to Nazarii Salish.

4 recordsLinked to original sources

arXiv2026

Approximate Factor Models for Functional Time Series

We propose a novel approximate factor model tailored for analyzing time-dependent curve data. Our model decomposes such data into two distinct components: a low-dimensional predictable factor component and an unpredictable error term. These components are identified through the autocovariance structure of the underlying functional time series. The model parameters are consistently estimated using the eigencomponents of a cumulative autocovariance operator and an information criterion is proposed to determine the appropriate number of factors. Applications to mortality and yield curve modeling illustrate key advantages of our approach over the widely used functional principal component analysis, as it offers parsimonious structural representations of the underlying dynamics along with gains in out-of-sample forecast performance.

econ.EM↗

arXiv2026

Practical Forecasting of Environmental Maps: A Functional Data Approach

Environmental problems are receiving increasing attention in socio-economic and health studies, fostering advances in recording and data collection of related real-life processes. However, traditional tools for data processing are often found too restrictive as they do not account for the rich nature of such data sets. In this paper, we propose a simple statistical perspective on forecasting environmental data collected sequentially over time across some predefined geographic region. We treat such data set as a surface (or functional) time series with a possibly complicated geographical domain. Using techniques from functional data analysis, we develop a forecasting methodology that allows to account for both geographic and temporal dependencies. This methodology allows integration of traditional multivariate techniques to provide forecasts surfaces. We demonstrate the practical value of our approach with a forecasting example of ground-level ozone concentration across Germany, showcasing its effectiveness and potential for broad application.

stat.ME↗

arXiv2026

Detection Boundaries for Panel Slope Homogeneity Tests Under Small-Group Heterogeneity

Empirical researchers often use slope-homogeneity tests to assess whether slopes can be treated as common across units. A key difficulty is that heterogeneity may be concentrated in a small number of units, so that a failure to reject homogeneity may reflect limited power rather than true homogeneity. We quantify this issue by analyzing the power of standard slope-homogeneity tests under doubly local alternatives - alternatives in which only small groups of units depart from the common slope and the magnitude of the deviations shrinks with sample size. We characterize detectability as a function of panel dimensions, the size of the departing groups, and the rate at which deviations shrink. The results tell the researcher clearly when homogeneity tests are informative and when they will miss small-group heterogeneity. A Monte Carlo study confirms the theory.

econ.EM↗

arXiv2024

Saving for sunny days: The impact of climate (change) on consumer prices in the euro area

Climate (change) affects the prices of goods and services in different countries or regions differently. Simply relying on aggregate measures or summary statistics, such as the impact of average country temperature changes on HICP headline inflation, conceals a large heterogeneity across (sub-)sectors of the economy. Additionally, the impact of a weather anomaly on consumer prices depends not only on its sign and magnitude, but also on its location and the size of the area affected by the shock. This is especially true for larger countries or regions with diverse climate zones, since the geographical distribution of climatic effects plays a role in shaping economic outcomes. Using time series data of geolocations, we demonstrate that relying solely on country averages fails to adequately capture and explain the influence of weather on consumer prices in the euro area. We conclude that the information content hidden in rich and complex surface data can provide valuable insights into the role of weather and climate variables for price stability, and more generally may help to inform economic policy.

econ.GN↗