Bhutan economy, one of the world's smallest and least developed, is based on hydroelectricity, tourism, agriculture, and forestry. Agriculture and forestry which provide the main livelihood employ almost 60% of the population and account for about 40% of GDP. However, Hydro-electricity remains the biggest revenue generator of Bhutan. The bigger chunk of the generated power is consumed by India. Other sources of revenue include tourism and minerals like coal, gypsum, cement production and ferro-chemicals. The economy is closely aligned with India's through strong trade and monetary links and dependence on India's financial assistance. The main industries of the country are cement, wood products, processed fruits, alcoholic beverages and calcium carbide. The industrial sector is technologically backward with most production of the cottage industry type. Most development projects such as road construction rely on Indian migrant labor.