This document provides a detailed technical description of the construction methodology used to develop Bilateral Longitudinal Observations and Country Statistics (BLOCS) database, version 4.0. BLOCS is an integrated panel database that systematically combines bilateral trade, investment, institutional, and macroeconomic data between 1948 – 2023 from 16 international sources. In addition to our standard codebook, this documentation examines the procedural architecture, sequential data processing, standardization protocols, and merging methodologies that transform disparate datasets into a coherent analytical resource. The briefing is structured to reflect the construction workflow, beginning with the foundational country code standardization (“Rosetta Stone” system), proceeding through individual dataset processing for trade (BACI, WTF), investment (UNCTAD, IMF) and institutional factors (Polity IV, WGI). It serves as a technical guide for users interpreting BLOCS variables and as a reproducibility framework for researchers interested in integrated economic data construction, addressing challenges like historical country transitions, identifier reconciliation, and scalable merging architectures for large-scale panel data. When reviewing the replication file some stages will appear out of order as some data has been grouped by category and historic tariff data was moved to the end. Continue Reading