The NDS was an agency of the Newman Association of Great Britain. It was founded in 1953 by Spencer and led by him until 1964. It recruited a large number of Catholic graduates and professionals with a social science or statistical background – up to 200 at the peak – working on a voluntary basis. Initially it focused on the size and age structure of the Catholic population, and the carrying out of a census of Catholic schools in January, 1955. Later that year it published estimates of the numbers of Catholic children, and the numbers in Catholic schools, both by age.

By 1955 it was clear that the Catholic Church’s pastoral and population statistics system needed a complete rationalisation. This started in 1956 and was completed by 1960. Reflecting its practical objectives the NDS prepared a planning study late in 1955 of the capacity of the Catholic teacher training system, and in 1958 was commissioned by the Catholic Education Council (CEC) to prepare another in the context of the impending massive expansion of teacher training in the country as a whole. This was completed in December, 1958, and had major consequences for the expansion of the Catholic colleges. The study also informed the Government decision, embodied in the 1959 Education Act, to halve – from 50% to 25% - the Catholic community’s share in the cost of new Catholic schools.

The 1958 study required the engagement of a salaried statistician, and this was followed by a gradual increase in the staff to a dozen in 1963. The NDS diversified into other areas. Its school census was repeated in 1959, and then annually (it continues to this day). It rolled out a programme of school planning studies for LEA areas, developed methodologies for parish censuses and parishioner records systems. It undertook for the International Catholic Migration Commission in 1959-60 a study of the arrangements for the integration of Irish immigrants in England & Wales. It carried out with the Young Christian Workers in 1957 a very large interview survey of young people in urban areas, and in 1961 a census of Catholic clergy and religious. But in 1963 Spencer was invited by the Newman Association to read a conference paper. If not, the bishops would withdraw support. The CEC objected to the text of the paper and insisted that he should withdraw from the conference. He did not comply, and in December the Catholic Bishops withdrew their support. On March 1, 1964, the educational work of the NDS, and the collection, editing and tabulation of the pastoral statistics, were taken over by the CEC. Spencer took the rest of the work with him to Cavendish Square Graduate College, and continued to work there with a small team under the name of Pastoral Research Centre. Early in 2005 the Catholic Bishops’ Conference de-classified all NDS reports and papers, leaving the PRC free to publish them.