This dissertation consists of three essays on foreign direct investment (FDI), or foreign equity participation, with analyses at the firm-level and beyond. The first essay (Chapter 2) investigates determinants of foreign equity participation at three levels —firm, country, and global region—and analyzes whether these determinants vary across global regions. In this pursuit, a firm-level dataset consisting of 197 surveys from 134 countries (67 of which covered two separate interview years—two surveys) is utilized in a multilevel logit framework. Countries are categorized into eight distinct developing global regions. Results suggest that obstacles faced by firms related to communication, finance, and institutional quality significantly (and negatively) affect foreign equity participation. Surprisingly, however, obstacles related to physical infrastructure actually seemed to attract foreign investment in some regions and those relating to administration uniformly encouraged foreign investment—suggesting that domestic firms may seek foreign equity participation in order to reduce or bypass administrative obstacles. Country-level attributes such as capital account openness, GDP per capita, inflation, and the rate of taxation on profits are shown to have varying impacts across regions—positive in some, negative in others, and statistical irrelevance in others. At the regional-level, intra-regional trade relative to regional GDP, was found to be positively associated with foreign equity participation for the aggregate data model but that relationship could be reproduced for only one region, South Asia, while the opposite seemed to be true for two regions, Central Asia and Middle East and North Africa. A higher (average) quality of governance in a region was found to stimulate the level of foreign equity participation. The second essay (Chapter 3) focuses on the productivity spillover effects of FDI using firm-level panel data from Brazilian manufacturing firms. Specifically, this study tries to determine what attributes of foreign-invested firms (FIFs) and domestic firms are associated with the transfer and absorption of spillover effects. Results suggest that, when spillover effects are measured at the aggregate level only, (positive) horizontal and backward productivity spillovers can be identified. However, when FIFs are disaggregated, those horizontal and backward spillover effects were found to be most closely associated with majority foreign ownership and high-export profiles. Additionally, we could now identify positive forward spillovers transmitted by low-importing and low-exporting FIFs exclusively to high-technology domestic firms. Finally, this investigation demonstrated that, for domestic firms, low productivity levels and the absence of worker training precluded the absorption of certain types of spillover effects but still allowed for the absorption of other (more passive) types of spillover effects. The third essay (Chapter 4) explores the effects of firm size on the productivity and spillover effects considering both continuous and discrete measures of size and using three measurement variables—assets, sales, and employment. A plant-level panel data set covering the Chilean manufacturing industries was utilized for the analysis. Results suggest that, when size is measured as a continuous variable, increasing domestic firm size in terms of assets was associated with falling productivity whereas increasing domestic firm size in terms of sales and employment was associated with increasing productivity. For FIFs, increasing size appeared to moderate what was a generalized negative forward spillover effect when assets and sales were used to measure size. For the discrete size measures, size implications for productivity largely reproduced the continuous measure results but findings of spillover effects were much more frequent. However, the direction and frequency of spillover effects varied with the choice of size measure and, for sales and assets, the disaggregation criteria. Thus, while all measures of size indicate a relationship between size and spillover effects, the frequency, nature and direction of spillover effects varied substantively with the type of size measure (continuous vs discrete) and the variable used to determine size.