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,