TY - JOUR A1 - Hassler, Uwe A1 - Hosseinkouchack, Mehdi T1 - Understanding nonsense correlation between (independent) random walks in finite samples T2 - Statistical papers N2 - Consider two independent random walks. By chance, there will be spells of association between them where the two processes move in the same direction, or in opposite direction. We compute the probabilities of the length of the longest spell of such random association for a given sample size, and discuss measures like mean and mode of the exact distributions. We observe that long spells (relative to small sample sizes) of random association occur frequently, which explains why nonsense correlation between short independent random walks is the rule rather than the exception. The exact figures are compared with approximations. Our finite sample analysis as well as the approximations rely on two older results popularized by Révész (Stat Pap 31:95–101, 1990, Statistical Papers). Moreover, we consider spells of association between correlated random walks. Approximate probabilities are compared with finite sample Monte Carlo results. KW - Coin tossing KW - Concordance KW - Discordance KW - Maximum length of association Y1 - 2021 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/63722 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-637223 SN - 1613-9798 N1 - Open Access funding enabled and organized by Projekt DEAL. VL - 63 IS - 1 SP - 181 EP - 195 PB - Springer CY - Berlin ; Heidelberg [u.a.] ER -