The Phillips-Perron unit root test was used to test for unit roots, using level or trend nonstationarity as the null [1]. (A unit root tests whether a variable y evolves as a random walk, i.e., with the dynamic relation yt = yt-1 + constant + deterministic trend + errort.) The KPSS test [1,2], which uses level or trend stationarity as the null, was used to confirm the results of the Phillips-Pe...

There is much interest in using network measurements for both modeling and operational purposes. In this paper we focus on the fundamental question of the stationarity of such measurements. That is, to what extent are past measurements a good predictor of the future? We used the NIMI infrastructure and a set of public traceroute servers to capture large measurement datasets of three quantities:...

Results: Empirical analysis uses a dataset of nominal interest rates, money growth, income growth, changes in nominal exchange rate, and budget deficit. From the methodological point of view the paper involves vector autoregression model and Wald tests of Granger causality, followed by impulse response analysis while stationarity and the order of integration of the selected variables are confir...