This episode's headline: Balancing Act; Political Wrap; Newsmaker; Changing Times; Peace for Bosnia?. ANCHOR: JAMES LEHRER; GUESTS: LAURA D'ANDREA TYSON, National Economic Adviser; MARK SHIELDS, Syndicated Columnist; PAUL GIGOT, Wall Street Journal; REP. JOHN KASICH, Chairman, Budget Committee; BARTLOMIEJ KAMINSKI, University of Maryland; JAMES GRAFF, Time Magazine; CORRESPONDENTS: KWAME HOLMAN; MARGARET WARNER; CHARLAYNE HUNTER-GAULT; ELIZABETH FARNSWORTH;