Marro, in his “I caratteri dei delinquenti”, gives us the following:
| Criminals. | Non-criminals. | |
| Without property | 79.6 % | 43.4 % |
| Minor children of well-to-do parents | 4.1 %,, | 10.5 %,, |
| With a little property | 6.7 %,, | 18.4 %,, |
| With considerable property | 9.4 %,, | 27.6 %,, |
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At the time that they committed their crimes 43% of these criminals in general, and more than 50% of the criminals against property were without work.
All that has been given above has to do with statics; what follows has to do with dynamics. The rule universally observed is this: modifications in economic conditions are followed by modifications in criminality. When the former grow worse, the number of crimes (and especially of those against property) increases, and vice versa. It is especially the proletariat, who have no means of resisting the unfavorable influence of crises, a rise in the price of food, etc., who are hardest hit in these cases.
The author gives some data. In Italy in 1880 a great increase of crime coincided with a lack of work and with a rise in the price of provisions. The gradual diminution in criminality must be attributed to the good harvest and the large emigration. In Belgium the number of prisoners rose during the crisis of 1846 from 6750 to 9884. In Norway, in consequence of the depression of 1869, crimes against property reached the maximum. The number of prisoners in Sweden rose from 1835 to 1839, chiefly because of poverty, from 12,799 to 18,357. A great increase in crime took place in England in consequence of the crises of 1826, 1830, 1847, and others. In the United States there were in 1884 not less than 400,000 working-men without work, which explains the following figures:
| 1883 | 1884 | |
| Homicides | 1,494 | 3,377 |
| Cases of lynching | 92 | 219 |
| Suicides | 910 | 1,897 |
In consequence of the economic crises of 1839, 1840, 1843, 1847, 1867, 1876, and 1881, the number of murders increased in France.[14]
The maximum stability and the minimum lack of proportion in the distribution of wealth is the best preservative against crime. The correctness of this rule is proved by the facts. The small number of crimes among the Irish is explained by their altruistic sentiments, which are the consequence of their social institutions from before the conquest of their country by the English. Among Mohammedans [[227]]crime is rare. Also there may be remarked among them a true democracy, based upon equality and fraternity. The Yorubas (in Eastern Africa) have a mild character, and they are benevolent and true to their word; with them the land is considered as common property, etc., etc.