Complex sentence: If the relationship parameter\\ beta is estimated by regressing the observed y_i on x_i, the resulting ordinary least squares regression will yield a downwards-biased estimate of the slope coefficient and an upwards-biased estimate of the intercept.
Split into simpler sentences: If the relationship parameter\\ beta is estimated by regressing the observed y_i on x_i, the resulting ordinary least squares regression estimator is inconsistent. It will yield a downwards-biased estimate of the slope coefficient and an upwards-biased estimate of the intercept.