41. In economic terms, pollution from fossil fuels is regarded as a negative externality . 42. Congestion is considered a negative externality by economists. 43. Furthermore, driving can impose hidden costs on society through pollution ( externality ). 44. The externality concept remains central to modern welfare economics and particularly to environmental economics. 45. Production of public goods are a textbook example of production that create positive externalities . 46. Such externalities prevent markets from operating efficiently, according to analyses of public economics. 47. But their current widespread use causes negative externalities . 48. Under complete markets pecuniary externalities offset each other. 49. The resource consumption or externalities embodied in this other consumption is the indirect effect. 50. *The effect of corporations on their environment is referred to as an externality .