WASHINGTON (MarketWatch) - The federal government should cut taxes on small businesses to encourage them to invest and hire more workers, President Barack Obama said Tuesday. Obama proposed that the federal government do more to help create jobs in three main areas: small business growth, infrastructure investments, and investments in energy-efficiency. The centerpiece of Obama's plan is a proposal for new tax cuts to encourage small businesses to invest and to hire more workers. The capital-gains tax on new investments would fall to zero for a year, and tax breaks for expensing investments would be extended. The plan also includes a still-to-be-designed tax cut for small business to hire more workers.