Evaluate export-crop support outcomes beyond participation.
Inputs, example and sources
World Bank · Impact Evaluation in Practice Second Edition
Institution publication · Chapter 7, table 7.2, printed page 140, PDF page 170
The formula is verified. Causal interpretation still requires a defensible study design, comparison and assumptions.
Keep the same place, observation period, definitions, units and source versions.
Analysis inputs. Treatment Enterprise gross margin before [LKR/ha]; Treatment Enterprise gross margin after [LKR/ha]; Comparison Enterprise gross margin before [LKR/ha]; Comparison Enterprise gross margin after [LKR/ha]; Study design and comparability evidence; Outcome definition, method and reference basis
Other required evidence. Supported growers; baseline margin; follow-up margin; comparison group; market conditions.
Fictional worked example · 2025
Laggala Pallegama — programme evaluation · Laggala Pallegama
| Input or result | Value | Unit |
|---|
| Treatment Enterprise gross margin before | 420,000 | LKR/ha |
| Treatment Enterprise gross margin after | 590,000 | LKR/ha |
| Comparison Enterprise gross margin before | 390,000 | LKR/ha |
| Comparison Enterprise gross margin after | 460,000 | LKR/ha |
| Study design and comparability evidence | Missing | |
| Outcome definition, method and reference basis | Enterprise gross margin /example matching definition1 | |
| Difference in changes | 100,000 | LKR/ha |
|---|
The arithmetic alone does not establish causation. Design, parallel trends, confounding, attrition, uncertainty and adverse effects need appropriate evidence.
Proposed checking role. Export-crop agronomist and market/quality specialist.
After the action. Verified outcomes, costs, distributional effects and evidence strength.
- World Bank Impact Evaluation in Practice Second Edition — Institution publication. Chapter7 difference-in-differences. Published difference-in-differences estimator and study assumptions; aggregate examples do not establish causation.
- SHARED domain decision contracts — Validation required. Domain decision rules and matching fictional examples. Local comparisons, constraints, source matching, sorting and follow-up proposals; developer checks do not establish scientific or client approval.
Institution and data context
Confirm local scope, data rights, parameters and responsible roles in this Institution review. Published components retain their source; they do not approve the local application.