This study provides an estimate of the size of the informal economy in the Nether lands in the period 1965-1982. In this study the informal economy has been defined statistically as that part of the non-registered national product which involves monet ary transactions. Bartering activities and transactions outside the market are thus left completely out of consideration. The same is true of those market transactions which, despite their illegal or underground nature, are already included in the national pro duct published by the Central Bureau of Statistics (CBS) because of its measuring...