“…Theoretically, this implies that the neoclassical growth model still retains the structure described in section 3.1, with the clarification that both technology and per capita GDP are I(2), and naturally, their growth rates are I(1). Authors who explicitly model GDP as an I(2) process within the state space models class include Clark (1987), Harvey andJaeger (1993), andTóth (2021). Importantly, this result does not impact my discussion, which simply aims to identify a connection between the millennia-long technology series and the per capita output series to assess the adequacy of its reconstruction.…”