  The tick value is a crucial component of market design and is often
considered the most suitable tool to mitigate the effects of high frequency
trading. The goal of this paper is to demonstrate that the approach introduced
in Dayri and Rosenbaum (2015) allows for an ex ante assessment of the
consequences of a tick value change on the microstructure of an asset. To that
purpose, we analyze the pilot program on tick value modifications started in
2014 by the Tokyo Stock Exchange in light of this methodology. We focus on
forecasting the future cost of market and limit orders after a tick value
change and show that our predictions are very accurate. Furthermore, for each
asset involved in the pilot program, we are able to define (ex ante) an optimal
tick value. This enables us to classify the stocks according to the relevance
of their tick value, before and after its modification.
