Abstract:More and more wealth have been spent on information technology (IT) investment over the last two decades, nevertheless the investment of IT to organizational performance also became an extremely important but highly controversial issue. Packed with the computation approach of Copula Bayesian estimation as the methodology and equipped with the constant elasticity of substitution production function as the theoretical foundation, this study attempts to examine the inputs complement and substitution relations among ordinary capital, ordinary labor, and IT capital in conjunction with the value of IT. The Copula Bayesian method is proposed in IT issue and fitted into a panel data set, using the analysis of correlation structure. The major findings include: the so-called productivity paradox is found to appear in both developed and developing country; IT investment has substantial impacts associated with the CES production function; and capital, labor, and IT capital at country level display a strong substitution rather than complement relationship. The structural differentiation of substitution is figured, using Copula Bayesian estimation, which has the strengthened central area in China. These phenomena have important implications for investment decisions at country level and the ignorance of these relationships means to over- or under- state the real value of IT and that the substitution structure among non-IT capital, ordinary labor, and IT capital is a technological and complex matter and must be seriously taken into account while assessing the impacts of IT at country level.