  Using a proprietary dataset of meta-orders and prediction signals, and
assuming a quasi-linear impact model, we deconvolve market impact from past
correlated trades and a predictable return component to elicit the temporal
dependence of the market impact of a single daily meta-order, over a ten day
horizon in various equity markets. We find that the impact of single
meta-orders is to a first approximation universal and slowly decays to zero (or
to a small value), possibly as a power-law. We show that auto-correlated
order-flows and trade information contents fully accounts for the apparent
plateau observed in the raw data. We discuss the possible bias introduced by
the quasi-linear assumption.
