The empirical evidence on shareholder activism and short-termism is, in fact, mixed.

In a paper recently posted on SSRN, Short-Termism and Shareholder Payouts: Getting Corporate Capital Flows Right, we explain that these shareholder-payout figures fail to provide convincing evidence—or indeed any evidence of harmful short-termism—because they are an incomplete and misleading measure of public-firm capital flows.

source: ML