Public-private partnerships (PPPs) are increasingly used to provide infrastructure services. Even though PPPs have the potential to increase efficiency and improve resource allocation, contract renegotiations have been pervasive.We show that existing accounting standards allow governments to renegotiate PPP contracts and elude spending limits. Our model of renegotiations leads to observable predictions: (i) in a competitive
I illustrate that the welfare improvement property of the Melitz model is due to the shape of the aggregate labor demand curve, which slopes upwards. By slightly changing some assumptions in the model, this curve may have a negative slope. In this case, increases in aggregate productivity result in a reduction in welfare. For example,
This paper investigates under which circumstances negotiating simultaneously over multiple issues or assets helps reduce inefficiencies due to the presence of asymmetric information. We find that a simultaneous negotiation over multiple assets that are substitutes reduces inefficiencies. The effect is stronger if goods are heterogeneous, and in this case the inefficiency can be eliminated altogether.
Intertemporal preferences are difficult to measure. We estimate time preferences using a structural buffer stock consumption model and the Method of Simulated Moments. The model includes stochastic labor income, liquidity constraints, child and adult dependents, liquid and illiquid assets, revolving credit, retirement, and discount functions that allow short-run and long-run discount rates to differ. Data
Public-private partnerships (PPPs) cannot be justified because they free public funds. When PPPs are desirable because the private sector is more efficient, the contract that optimally trades demand risk, user-fee distortions and the opportunity cost of public funds is characterized by a minimum revenue guarantee and a cap on the firm’s revenues. Yet income guarantees
En este trabajo se estudia el grado de sustitución entre la telefonía fija y móvil en Chile. Los resultados muestran que la posesión de al menos un teléfono móvil en el hogar reduce el gasto promedio mensual en teléfono fijo en aproximadamente $5400 (31%). A pesar de lo anterior, el cambio estimado en el gasto
This paper considers a general optimal auction problem, with many goods and with a buyer’s utility that can depend non-linearly in his type. We point out that incentive compatibility constraints may be binding even if virtual utilities are strictly increasing in the buyer’s type. More importantly, optimal mechanisms may involve randomizations between different allocations.
In this article, we pursue to determine which mining firms have seen their stock returns become more sensitive to fluctuations in energy prices, over a time period predominated by the political turmoil caused by 9/11 and the subsequent invasion of Iraq. By resorting to wavelets and spatial statistics, we characterize the behavior of volatility and
This paper studies revenue maximizing auctions when buyers’ outside options depend on their private information. The set-up is very general and encompasses a large number of potential applications. The main novel message of our analysis is that with type-dependent non-participation payoffs, the revenue maximizing assignment of objects can crucially depend on the outside options that
This article presents a model to select the optimal hedge ratios of a portfolio comprised of an arbitrary number of commodities. In particular, returns dependency and heterogeneous investment horizons are accounted for by copulas and wavelets, respectively. We analyze a portfolio of London Metal Exchange metals for the period July 1993-December 2005, and conclude that
In this paper we characterize the optimal procurement mechanism and the investment level for an environment where two projects must be adjudicated sequentially, and the winner of the first project has the opportunity to invest in a distributional upgrade for its costs in the second project. We study 4 cases, based on the commitment level
