“…When little data is available, whether experimental, from post-earthquake feedback or from numerical calculations, a classic approach to circumvent estimation difficulties is to use a parametric model of the fragility curve, such as the lognormal model historically introduced in [1] (see e.g. [5,6,7,8,9,10]). As the validity of parametric models is questionable, non-parametric estimation techniques have also been developed, such as kernel smoothing [8,9] as well as other methodologies [10,11].…”