Recently, the Institute for Criminal Policy Research (ICPR) published the report Prison: Evidence of its use and over-use from around the world , which aims to offer a view of the state of the situation based on data available and use and over-use linked to prisoning policies.
The authors point out, from the beginning and for each of the countries, what the most important deficits faced by penitentiary and detention systems are.
Grouping them in terms of countries, those which may be considered to be developing countries, stress the benefits caused by the “overcrowding” of penitentiary centres and aspects related with an institutional weakness which can lead to bad conditions for prisoners, corruption or the control of prisons by groups of organised crime. The most paradigmatic example is Brazil, which suffers from all of these deficits.
A second group of countries, the developed ones, also have some deficits which are shared by the other countries included in the report. The most important and evident one is the ethnic or foreign population bias which exists between the penitentiary population and that of the country. Another element, which entwines with the previous one, is criminalisation of the vulnerable population. The most attention-grabbing cases in this area are the United States, Australia and Hungary.
But beyond the deficits of the system, the authors centre part of the debate on ratios of prisoners per one hundred thousand inhabitants, the reasons they give and some solutions to try to reduce these ratios.
Of the 10 countries included in the study, the USA is the country with the world’s biggest prison population, (2,145,100 inmates) and the second highest in relation with its ratio, 666 inmates per 100 inhabitants. Other countries which are close behind in overall numbers are Brazil, fourth in the world, India and Thailand, fifth and sixth in the ranking. Concerning ratios, far behind the US is Thailand in tenth place and Brazil in 32nd place.
Finally, among the reasons given to explain these ratios the authors group them in terms of criminality, legal framework, institutional, social and domestic politics and international. Paradoxically, among the multiple aspects presented, a range of them are developed, and if they are worked on, they may help to rationalise the number of inmates. The following are to be stressed; politicisation of justice, imprisonment of low profile inmates, over-representation of ethnic, national or social groups in prisons, hardening of policies against public health (drugs), too much time in detention before trial and finally, alternatives to prison once the objective of the prisoning process has been met.
 The countries concerned are; Kenia, South Africa, Brazil, the United States, India, Thailand, England and Wales (in this case this is not the United Kingdom), Hungary, Holland and Australia.
 Kenia, Brazil, South Africa, India and Thailand.
 It has the third highest ratio of inmates of the 10 countries studied (301/100,000 inhab), it apples hard legislation against crimes against public health (drugs) which penalises the most vulnerable sectors of the population, a public and political opinion in favour of a tough response, 68% of the prison population is black/mulatto when they represent 51% of the population, overcrowding of prisons which are controlled by organised gangs.
In 2000, there were 7.7 black prisoners and 2.7 Hispanics for each white inmate. The latest available data in the report are from 2015 and show a certain improvement, 5.7 black prisoners and 2.3 Hispanics for every white prisoner.
 In 2016, 27% of the penitentiary population was “Australian aborigine”, when they only represent 2% of the population.
 The Hungarian case stands out because of the government’s move to the right, and the accumulation of problems which have warranted warnings from the European Court of Human Rights (TDEH), with its respective recommendations and a very negative report from the US State Department, both in 2015. According to these reports, the most noteworthy problems are police corruption, brutality especially against the gypsy population, intimidation of civil society and the overcrowding and the poor conditions of prisons.
 In terms of published public opinions and policies which influence experts when designing legislation and penitentiary policies.
 In Holland, 24% of the penitentiary population is there although their trail has not begun, and this has a maximum duration of 104 days. However, this is not the longest period of time, we have France, Slovakia and Spain where it may be up to 4 years or Romania and Sweden which have no limit for detention.
 In this case, experts speak of up to 5 objectives; unfounded reports, punishment or repair, deterrent, incapacitation or rehabilitation.