International Journal of Psychosocial Rehabilitation, Vol. 24, Issue 02, 2020 ISSN: 1475-7192 4816 Trade fundamentals: A systematic review Sunday Elijah A, B , Hanny Zurina Hamzah A, *, Law Siong Hook A , Shivee Ranjanee Kaliappan A elijahsundayecons@gmail.com, hannyzurina@upm.edu.my, lawsh@upm.edu.my, shivee@upm.edu.my Abstract - This paper analyzed literatures on trade in a systematic way. A general study of trade was conducted, the review covered several theoretical, empirical and methodological literatures built as an attempt to overcome the concept-related measurement issues. Some of the models are largely theoretically based and well- motivated, the most desirable status credibility test may be detail evaluation of the appropriateness of some of the theoretically defined fundamentals. It looked at gravity model, HO model, computable general equilibrium, simple model of partial equilibrium, multidimensional concept of trade openness, preferential trade agreement and Heckman’s two stage selection method, which all have relationship with trade and are used in trade theories. It further discussed how household consumption variety is limited by distance from markets and trade restrictions; why visa restrictions could have an effect (barrier) on international trade in goods; elaborated the hypothesis that countries specialization is the endogenous firm’s outcome creative response caught out-of-equilibrium through changing conditions of product and factor market; assessed trade policy uncertainty – faced by Chinese exporters to the U.S; among other reviews. The paper leads researchers to further understand the nature and structure of trade, helping to build a consistent and reliable theory framework that is applicable to academics and practitioners. Keywords - Trade; Review; Systematic; fundamentals. _____________________________________________________________________________________________ 1 I. INTRODUCTION This literature review centered on trade; the significance is being underscored by the relevance of the reference subject. Trade is simply defined as the total of import and export which are measured as a share of the gross domestic product [1; 2]. The increase of trade openness has important impact on the economic growth [3]. Looking at the trend of globalization, many developing countries have open economic policies with developed countries in order for them to have a rapid economic growth and development. Trade has been treated as one of the important determinants of countries development. This paper contributes to literature by providing some arguments on existing literatures. The remaining part of this study consist of: first, theoretical literature and various terminologies mostly used in relation to trade are explored. Second, definitions of trade at various levels are presented along with the empirical literature. Third, the articles included methods and the measure of trade which is presented in the methodological literature. Finally, in the conclusion, some concluding highlights are presented. A Department of Economics, School of Business and Economics, Universiti Putra Malaysia, B Department of Economics, Federal University Gusau, Zamfara State, Nigeria. *Corresponding author: Hanny Zurina Hamzah. Email: hannyzurina@upm.edu.my