A Theory of One-Size-Fits-All Recommendations

One-size-fits-all recommendations are common in many contexts, including those with a widespread heterogeneity. We propose a model that rationalizes this phenomenon. An expert recommends publicly to two agents whether to adopt a policy. The expert is privately informed about agents payoffs from the policy and his conflict of interest. We show that one-size-fits-all recommendations can be informative even when payoffs are independent across agents. Such recommendations increase the expert's influence by concealing his conflict of interest. We apply the model to recommendations provided by the IMF, World Bank, proxy advisory firms, central banks, and the Basel Committee.