I Introduction

This report presents the findings from a review of child support models used in ten jurisdictions: the United Kingdom, Australia, France, Norway, Sweden, New Zealand, and in four American States: Wisconsin, Delaware, Illinois, and Vermont.

Given the complexity and magnitude of the information collected in this study, the results are presented in two volumes. Volume I (Review of International Child Support Models – Main Report) presents an overview of the findings and includes several tables that provide a synthesis of various aspects of the child support models across jurisdictions. These tables can be found at the end of each chapter. Volume II contains summary reports for the ten jurisdictions and provides a description of the various aspects of the child support model in that jurisdiction. Throughout Volume I, the reader is encouraged to consult the relevant summary report if more detailed information is desired.

Among the challenges in conducting this study were the terms used in the ten jurisdictions to describe the various elements of their child support models. Each jurisdiction uses terminology that is unique to them. To assist the reader, the report uses “jurisdiction neutral” terminology in both Volumes I and II. The definitions of these terms can be found in the Glossary at the beginning of this report.

In the summary reports, if a jurisdiction uses a term that is not the same as the “jurisdiction neutral” term, a footnote is provided that indicates the term used in that jurisdiction. The only exception, however, pertains to the terms used in the formula calculations as these refer to specific calculations and cannot be altered without changing their meaning. These terms have been italicized to assist the reader.

This review was conducted between November 2018 and August 2019 on behalf of the Department of Justice Canada.

A. Objectives of the Study

As part of ongoing legal policy work, the Department of Justice Canada required that an extensive review be undertaken of a number of international models relating to determining child support amounts. The overall purpose of the research was to review and analyze child support models in ten jurisdictions to identify how issues related to the determination of child support are addressed.

The specific objectives of this study were as follows:

B. Research Framework

A research framework was developed to structure the lines of inquiry for the international review. This framework is used in Chapter II to summarize the research that informed the development and implementation of the Canadian Federal Child Support Guidelines. As well, it was used to inform the literature review and interviews with the ten jurisdictions.

The framework consists of three components, described below.

1. Rationale for the legal framework

This component consists of a description of the rationale and philosophy underpinning each jurisdiction’s child support model. Included in this component is a discussion of the impetus and rationale for the development of the model, and the overall objectives. It includes:

2. Description of the formula or approach used to calculate child support amounts

This component includes a description of the formula or approach used by each jurisdiction. Each formula generally comprises two elements:

Element 1: An approach to estimate the amount that best approximates the “expenditures on children.”

Element 2: An approach to apportion the amount between the two parents.

The literature review and interviews with child support experts collected information on the following aspects of each jurisdiction’s formula:

In addition, information was collected on the following underlying child support policies that may have been considered when developing a formula and child support model:

3. Accompanying rules set out in policy/legislation to generate the final child support amount

This component includes a description of the accompanying rules as set out in legislation and court rules that determine the final child support amount. Accompanying rules include:

C. Methodology

The study involved an extensive international literature review and environmental scan, as well as interviews with child support experts from the selected jurisdictions on their respective jurisdiction’s child support model.
The main steps are outlined below.

1. Selection of the jurisdictions

The purpose of this study was to provide a detailed overview and analysis of child support models in ten jurisdictions. Thus, it was important to ascertain what type of model jurisdictions use to assist separating or divorcing parents to calculate child support amounts. A goal was to ensure that the jurisdictions chosen for this study adequately reflected the range of various models14 in existence. In addition to ensuring that the selected jurisdictions adequately represented the range of administrative models used to determine child support amounts, it was also necessary to ensure that the study included the various apportioning approaches that underpin child support formulas. Although there are numerous types of child support formulas, most are rooted in one of three general apportioning models15. They are:

Based on our assessment against the above noted criteria, the ten jurisdictions listed at the beginning of this chapter were selected for examination. 

2. International literature review and environmental scan

A review of the international literature focused on research, commentary, critiques and evaluations of child support models used internationally. Family justice/law journals, government documents and well-known websites that deal with child support issues were the focus of the search.

The results of this literature review were analyzed and summarized to provide an overview of the key issues that jurisdictions currently address in the development and implementation of their child support models. The results of this literature review also informed the lines of inquiry for the jurisdictional interviews.

3. Interviews of child support experts in the selected jurisdictions

Telephone interviews with at least one child support expert in each jurisdiction were conducted. After having identified experts who were knowledgeable about the jurisdiction’s policy and operation of their child support guidelines, a letter of introduction was sent by the Department of Justice Canada requesting participation in the study. To facilitate the discussion, a draft country summary as well as a tailored interview guide was prepared and sent to the key informants in advance of each interview.


14 The definition of “child support model” includes whether or not the jurisdiction uses child support guidelines to determine a child support amount, the legislative framework that outlines how the child support guidelines are to be implemented, and the mechanism for administration – ranging from an administrative model to relying on their family court system to make the determination, or a combination of both.

15 These definitions are taken from the following document: United States National Conference of State Legislators (NCSL), Child Support Guideline Models By State, 2019,  http://www.ncsl.org/research/human-services/guideline-models-by-state.aspx

16 Sometimes referred to as fixed percentage model, flat percentage model or percentage model.