Strategy-Proof and Envy-Free Random Assignments
We study the random assignment of indivisible objects among a set of agents with strict preferences. We show that there exists no mechanism which is unanimous, strategy-proof and envy-free. Weakening the first requirement to q-unanimity – i.e., when every agent ranks a different object at the top, then each agent shall receive his most-preferred object with probability of at least q – we show that a mechanism satisfying strategy-proofness, envy-freeness and ex-post weak non-wastefulness can be q-unanimous only for q ≤ 2/n (where n is the number of agents). To demonstrate that this bound is tight, we introduce a new mechanism, Random-Dictatorship-cum-Equal-Division (RDcED), and show that it achieves this maximal bound when all objects are acceptable. In addition, for three agents, RDcED is characterized by the first three properties and ex-post weak efficiency. If objects may be unacceptable, strategy-proofness and envy-freeness are jointly incompatible even with ex-post weak non-wastefulness.
Populist Leaders and the Economy
Populism at the country level is at an all-time high, with more than 25% of nations currently governed by populists. How do economies perform under populist leaders? We build a new cross-country database identifying 50 populist presidents and prime ministers 1900-2018. We find that the economic cost of populism is high. After 15 years, GDP per capita is more than 10% lower compared to a plausible non-populist counterfactual. Rising economic nationalism and protectionism, unsustainable macroeconomic policies, and institutional decay under populist rule do lasting damage to the economy.