Economic Theory, Econometrics, and Mathematical Economics: Quantitative Economics and Development: Essays in Memory of Ta-Chung Liu focuses on the advancements in the methodologies and processes in the field of quantitative economics. The selection first offers information on society, politics, and economic development, global stability of stochastic economic processes, and the design of mechanisms for the efficient allocation of public goods. Discussions focus on the design of individually incentive compatible mechanisms in an abstract setting, design problem under coalition formation, stability results for the economic models, invariant measures for diffusions, and disjoint principal-components method. The text then takes a look at critical observations on the labor theory of value and Sraffa's Standard Commodity and a generalization of Hotelling's solution. The manuscript examines an exploratory policy-oriented econometric model of a metropolitan area and the effect of simple specification error on the coefficients of "unaffected" variables, including distinctive features of the model and individual sectoral models. Temporal aggregation and econometric models; uniqueness of the representation of commodity-augmenting technical change; and technological change and growth performance in Taiwan agriculture are also discussed. The selection is a valuable source of data for economists and readers interested in quantitative economics.