1.      Investment in education
The cost-benefits in strengthening abilities of persons to be satisfied by increasing productivity and acquiring knowledge and using it in actualising the maximum potentials for development is investment in education (Deveraj & Hebbar, 1999).
Investment in education is the cost-benefit analysis of expenditure on education to increase human capital.  Improved skills and knowledge bring high rates of return to investment in human capital. Cost and benefit analysis in education is carried out through three assumptions.  First, the value of money is expressed through comparative rates of returns to education. Second, the choice of individual and social investment in education is determined by the relative rates of return to alternative forms of education. Third assumption is, in a result of both the assumptions, future mode of financing is determined by relative values of rates of returns to levels of education (Francis, 1993). 
Education is considered an important form of investment in human development. Education improves the quality of life of humans through developing mental abilities, improving skills and efficiencies in producing useful things. For example an individual acquires knowledge about electrical energy and develops skills about making use of that energy and creates an electric generator, which generates electricity for producing other useful thing. This way peoples’ wants are satisfied and economic rates of return to education are also increased.  According to economists there is much difference between contribution of education to satisfaction of wants of educated people and the contribution which skilled and productive workers will make by producing qualitative and greater quantitative goods (Machlup, 1991).
(Qureshi, 1991) says that investment in education is cost-benefits analysis that people make in developing their skills and efficiencies and in self-improvement through schooling and training. Investment in education raises the productivity of human resources. For example costs in education may be expenditures that society affords for individuals for their schooling, parents spend on tuition fee, buying stationery, uniform and pocket money and in other terms time spent and hard work by individuals are also included in costs on education. Benefits are of two types; private benefits and social benefits. Private befits are long lasting earnings, more chances of employability, and longevity. Social rates of return are increased numbers of productive workers helping improving economy of society, contribution in planning for future development of society, reduced rate of population growth, improved standard of hygiene and a source of educating new generations. 
According to Haq and Haq (1998), social rates of return are highest in investment in primary education. When national income increases, overall returns at all level of education decline but rates of return to primary education still gets highest position. For example in primary education, costs involving money and time are less but their contribution in increasing income of the society is more, working in labour markets with literacy,  numeracy, problem solving, knowledge, skills, values and attitudes. 
According to Johnes (1993), some of the features of investment in education are; a) rates of returns are greatest when the investment in education is made early in life. For example children are sent to school so that they will start earn earlier and for a long period of time. b) The lower the cost of marginal unit involve in human capital the greater will be the investment. c) Returns are greater when more investment is made in education. This means that those who are fast learners and expecting high earnings in future will invest more in education. For example a doctor earns more than a nursing assistant. Thus the doctor tends to invest more for specialisation in his field keeping higher earning in future. d) Investment in education will occur so long as the marginal benefits exceed or equal to the marginal costs.
Education as investment
Investment means spending now on something that can be expected to generate an income in future. Education as investment implies exchange of current income opportunities with better income chances in future.  Human capital is produced when more resources are used in schooling. If an individual demands more education in order to increase his/her market value it is better to do so in early stages of life. He /she benefit from increased earnings building up from additional human capital for as long as possible (Checchi, 2006).
On the basis of above small discussion, education as investment can be explained as it is the investment of previously acquired knowledge, skills and competencies. It is also investment of cost opportunities which could be gain using existing knowledge, skills and competencies within the period in which additional production skills are acquired. In result of such investment, productive skills are improved and chances of higher earning are increased. For example an individual after doing his/her B. Ed can be a teacher and earns sufficient amount of money. Then he/she looks forward after a certain period that earning after M. Ed may be increased, so he/she spends two more years for increasing his/her productivity through acquiring in depth knowledge, skills and competencies. During two years of earning which is known as opportunity costs is invested for further chance of higher earning.
Earning opportunities or productivity can also be increased by increasing the knowledge, skills and competencies within the job through trainings or other techniques of developing skills. For example conducting a research relevant to the field or getting training of a new program of computer may also improve the capacities of an individual. For that purpose an individual invests time, knowledge, skills and money for improving research skills or learning new program of computer which brings about a significant change in his earnings. As in the following lines it is supported by literature.   
Job-related training and continuing education plays a significant role in increasing the stock of knowledge and skills in today’s rapid changing world. As technology becomes more advanced each year and new tools are introduced in communication, calculation and production, acquiring new skills becomes a necessity for increasing the chances of earnings (Xhaferri and Iqbal, 2008).
Education as consumption
Education provides utility to individuals. Utility is defined as the application of knowledge, skills and abilities acquired during educational process by an individual. If individuals use them to fully enjoy life, appreciate literature and culture, for a short time for getting pleasure, education is considered as consumption (Johnes, 1993). Consumption is in sense that investment is made in education for increasing the productivity of individuals but the education that does not satisfy needs of individuals is known as consumption. For example an individual who gets a masters degree in geology (this is a live example I refer to) but can not be able to earn using that degree and finally any way he gets a job in a bank where he needs to learn knowledge and skills required in banking which he improves working in the bank. In this case education in geology is consumption because it gives him only pleasure of being masters degree holder.

Education as consumption refers to use of its utility to satisfy wants. Education is also a private consumption, because people spend on it for acquiring qualifications and training to fulfill their wants. It is also public consumption, because the government spends huge amount on the education system. At the moment regular education is clearly consumption, since individuals spend their earnings and government spends taxes collected from individuals for future benefits over a long period of time (Sawada, 2003).

Filmer & Pritchett (1998) is of the view that parents always demand for quality and quantity in education for productive individuals in returns to their expenditure on education. Quality in education needs higher expenditures from learners and from the state which is known as subsidy to education. For poorer parents it is difficult to spend more on education because they can not afford the expenses of higher education and also if they are engaged in earnings they can earn to some extent. While on the other hand if quality is not focused and quantity is preferred to benefit more students by increasing enrolments, then children from rich families shift schools. For children from rich families, basic education supports their higher education, so they spend on basic education to acquire knowledge and skills.  In both the cases children may be drop out. For example in a private school which is of average level by performance. Children from poor and rich households join the school for basic education. After a certain period children from rich parents shift the school for better quality and the children of poor households leave the school looking at earning from working out side the school. So in first case shifting the school and in second case drop outs lead education as consumption.

On the basis of above discussion, a contrast can be shown between education as investment and education as consumption given in the following. 
In perspective of education as investment, time and money is spent to increase income through productivity while education as consumption expenditure is made on education for satisfying the wants of individual and society. 
Knowledge, skills and abilities are used to acquire more knowledge, skills and abilities in education as investment while knowledge, skills and abilities are used to enjoy learning in education as consumption.
Education as investment will have its impacts such as generating income resources on individual and society after a longer period and for a longer period while impact of education as consumption such as pleasure of learning is immediate and for a short period of time. 
Efficiency rational of education is concerned with the education as investment while equity rational of education is concerned with education as consumption. Education is considered to improve efficiencies of the individual Efficiency rational while education is thought to provide equal distribution of knowledge, skills and abilities to the individual in equity rational of education.
References
Checchi, D. (2006). The economics of education: human capital, family background and   inequality. New York: Cambridge university press.   
Deveraj, K. V. & Herbbar, B. G. (1999). Education: Challenges of the twenty-first       century. In. K. Ghandi (Ed.), Education and development, pp. 138-142. New Delhi:           Vikas.
Machlup, F. (1991). Issues in the theory of human capital: education as investment. In. E.          A. Qureshi (Ed), development planning in Pakistan (pp. 431-443). Lahore:     Ferozsons.
Sawada, Y. (2003). Income risks, gender and human capital investment in a developing    country. University of Tokyo. Retrieved January31, 2009, from www.e.utokyo.          ac.Jp/cirje/ research/dp/2003/2003cf198.pdf.
Xhaferri, R. & Iqbal, K. (2008, February 24). Tailor made education. Dawn. Retrieved            January 09, from http://www.dawn.com/weekly/education/arch/arch_2009.htm