The value a director provides to a firm is empirically hard to establish. We estimate that value by exploiting the commonality in idiosyncratic returns of firms linked by a director and show that, on average, a single director's influence causes variation in firm value of almost 1% per year. The...

We investigate whether investor reactions to the announcement of a new outside director appointment significantly depend upon the director's experience in the appointing firm's industry. Our sample includes 688 outside director appointments to boards of S&P 500 companies from 2005 to 2010. We...

We proxy for board members' opinions and values using directors' ancestral origins and show that diversity has costs and benefits, which lead to high performance volatility. Consistent with the idea that diverse groups experiment more, firms with ancestrally diverse boards have more numerous and...