SANTIAGO, Dec 15 (Reuters) - Chile will go to the polls to elect a new president on Sunday, a stark choice between leftist former student protest leader Gabriel Boric and ultra-conservative Jose Antonio Kast. After a fragmented first-round vote, both candidates have shifted towards the center to attract moderate voters, though still offer wildly different views for the future of the copper-rich Andean nation of some 19 million people. Here are some of their key policies. SOCIAL ISSUES Boric has pledged to make advances on issues of gender equality and reproductive rights, including loosening Chile"s strict abortion rules, and improve inclusiveness for the LGBT community. Kast is opposed to same-sex marriage and abortion, preferring to focus on "family-focused" policies such as family payouts, formal recognitions for childcare work and incentives to have babies. He has made promises to improve women"s rights. PENSIONS Boric has taken aim at Chile"s privatized pension system, which many say gives too low payouts to savers. He wants a collective pensions model and has proposed a basic pension of some $300 per month. Kast proposes opening up the pension sector to new players to improve competitiveness. LAW AND ORDER Kast has made law and order one of the main pillars of his campaign. Policies include the creation of a new security committee to keep "public order," reforms to the armed forces, and creation of a special judiciary. He says he would take a tougher line on protests and indigenous clashes in the country"s south. Boric has in recent week beefed up his rhetoric on prosecuting crime, improving the police, and ensuring safety. TAXES Boric proposes raising the tax-to-GDP ratio by at least 5 percentage points during his government, with increases in corporate tax, green taxes, wealth taxes and mining royalties, as well as the elimination of some exemptions. He also plans measures to cut tax evasion. Kast"s original policy plan included a significant tax cut, but his advisers have since recommended that the readjustment be done gradually to ensure sufficient fiscal funding. MINING Boric has proposed in his plan to establish a higher mining royalty than is currently in force, similar to a bill being debated in Congress. His plan includes a tax linked partly to the mineral value and partly to operating margins. He has proposed a state firm to get involved in the lithium sector. Kast at one point proposed to ​​open up state copper giant Codelco to more private investors, though has since walked back the idea. Mining firms are generally more amenable to Kast, though neither candidate made the sector a major campaign focus.