This dissertation contains two empirical essays. Each one addresses a long-standing economics question. The first essay extends a measure of the benefits that new products bring to society and uses it to value the introduction of the minivan. The second essay estimates firm-level productivities in Chilean manufacturing industries to learn about the dynamics of productivity. The common theme of both essays is the econometrics used; in each case, estimators are formulated to accommodate the generality of the stochastic processes associated with the unbalanced panels used in these measurements. Measurement of new product benefits is typically frustrated by the lack of observed new product price variation. This shortcoming in observed data p...