The aim is to develop a novel method for the quantification of indirect temporal connectivity that overcomes some limitations of existing methodology. This aim shall be achieved by providing a numerical connectivity indicator on a continuous scale that accounts for weekly frequency of connections and allows for a sub-division by markets of interest on a city-pair, country and world region level as well as two-level combinations.

The procedure is based on an algorithm that tests the null hypothesis that two events are distributed independently (by chance) and have a constant probability per time unit. Individual arrivals and departures are conceptualised as events, with a week as the time unit. At a pre-set significance level, the time span within which an arrival is followed significantly more often by a departure than can be expected by chance is calculated. This time span is termed a critical interval. Whenever two events occur within a critical interval at least twice within the given timeframe, a pattern (high quality indirect connection) is found.

The ratio of patterns found (high quality indirect connections) per events (individual arrivals and departures) is used as the core measure of indirect temporal connectivity. This measure is termed the pattern/event rate.