7 them and shall have access to support and counselling from, and the opportunity to consult with, the competent authority. 19.2 Volunteers should encourage offenders and their families to develop meaningful ties with the community and a broader sphere of contact by providing counselling and other appropriate forms of assistance according to their capacity and the offenders' needs. 19.3 Volunteers shall be insured against accident, injury and public liability when carrying out their duties. They shall be reimbursed for authorized expenditures incurred in the course of their work. Public recognition should be extended to them for the services they render for the well-being of the community. VIII. Research, planning, policy formulation and evalution 20. Research and planning 20.1 As an essential aspect of the planning process, efforts should be made to involve both public and private bodies in the organization and promotion of research on the non-custodial treatment of offenders. 20.2 Research on the problems that confront clients, practitioners, the community and policy-makers should be carried out on a regular basis. 20.3 Research and information mechanisms should be built into the criminal justice system for the collection and analysis of data and statistics on the implementation of non-custodial treatment for offenders. 21. Policy formulation and programme development 21.1 Programmes for non-custodial measures should be systematically planned and implemented as an integral part of the criminal justice system within the national development process. 21.2 Regular evaluations should be carried out with a view to implementing non-custodial measures more effectively. 21.3 Periodic reviews should be concluded to assess the objectives, functioning and effectiveness of non-custodial measures. 22. Linkages with relevant agencies and activities 22.1 Suitable mechanisms should be evolved at various levels to facilitate the establishment of linkages between services responsible for non-custodial measures, other branches of the criminal justice system, social development and welfare agencies, both governmental and non-governmental, in such fields as health, housing, education and labour, and the mass media. 23. International cooperation 23.1 Efforts shall be made to promote scientific cooperation between countries in the field of noninstitutional treatment. Research, training, technical assistance and the exchange of information among Member States on non-custodial measures should be strengthened, through the United Nations institutes for the prevention of crime and the treatment of offenders, in close collaboration with the Crime Prevention and Criminal Justice Branch of the Centre for Social Development and Humanitarian Affairs of the United Nations Secretariat. 23.2 Comparative studies and the harmonization of legislative provisions should be furthered to expand the range of non-institutional options and facilitate their application across national frontiers, in accordance with the Model Treaty on the Transfer of Supervision of Offenders Conditionally Sentenced or Conditionally Released.