A recursive algorithm for estimating linear models with both constant and time-varying parameters is derived by maximization of a likelihood function. Recursive formulas are also derived for derivatives of the likelihood function; the derivatives are needed for numerical evaluation of some...

The paper considers the benefit to agricultural producers from commodity price insurance that provides in every year, but in advance of the resolution of production and price uncertainty, a minimum price for a fixed or variable portion of production. Under the assumption that producers do not...

This paper explores the impact of the recent soar in world commodity prices on economic activity and household welfare in Tanzania, and the possible policy responses to that shock. The analysis is based on a single country computable general equilibrium model that includes considerable factor...

"Food policy often depends on markets and markets depend on institutions. But how good do institutions have to be before reforms can be launched? Relying on well timed surveys of agricultural prices and a joint study by the Government of Bulgaria and the World Bank on agricultural market...

The problem of simultaneously identifying and controlling a time-varying, perfectly-observed linear system is posed. The parameters are assumed to obey a Markov structure and are estimated with a Kalman filter. The problem can be solved conceptually by dynamic programming, but even with a...

A recursive algorithm for estimating linear models with both constant and time-varying parameters is derived by maximization of a likelihood function. Recursive formulas are also derived for derivatives of the likelihood function; the derivatives are needed for numerical evaluation of some...

Food policy often depends on markets and markets depend on institutions. But how good do institutions have to be before reforms can be launched? Relying on well timed surveys of agricultural prices and a joint study by the Government of Bulgaria and the World Bank on agricultural market...

Studies of risk and its consequences tend to focus on one risk factor, such as a drought or an economic crisis. Yet 2003 household surveys in rural Kilimanjaro and Ruvuma, two cash-crop-growing regions in Tanzania that experienced a precipitous coffee price decline around the turn of the...