“…As the chair-CEO age difference may change due to chair and CEO changes, which are likely to correlate with the firm's performance and number of board meetings, these two controls are necessary to separate the (persistent) effect of the variables measuring the chair-CEO age dissimilarity from the (one-off) effects of changes at the top of the firm. Free float (of the firm's voting shares), R&D expenses as a fraction of total revenues (R&D/Sales), return on equity (ROE), Sales growth (i.e., the nominal growth rate over the past two years), Stock volatility (i.e., the standard deviation of daily stock returns over the past two years) and Total assets as used in the existing literature (e.g., Andres, 2008;Bebchuk et al, 2009;Bhagat andBolton, 2008, Custódio andMetzger, 2014).…”